diff --git a/doc/python_api/sphinx_changelog_gen.py b/doc/python_api/sphinx_changelog_gen.py
index aca8214b830..f2c8ff38e18 100644
--- a/doc/python_api/sphinx_changelog_gen.py
+++ b/doc/python_api/sphinx_changelog_gen.py
@@ -101,7 +101,7 @@ class JSONEncoderAPIDump(json.JSONEncoder):
 
 
 def api_dump(args):
-    import rna_info
+    import _rna_info as rna_info
     import inspect
 
     version, version_key = api_version()
diff --git a/doc/python_api/sphinx_doc_gen.py b/doc/python_api/sphinx_doc_gen.py
index 4828da2062a..4a5a335a04a 100644
--- a/doc/python_api/sphinx_doc_gen.py
+++ b/doc/python_api/sphinx_doc_gen.py
@@ -57,7 +57,7 @@ except ImportError:
     print(__doc__)
     sys.exit()
 
-import rna_info  # Blender module.
+import _rna_info as rna_info  # Blender module.
 
 
 def rna_info_BuildRNAInfo_cache():
diff --git a/scripts/addons_core/pose_library/gui.py b/scripts/addons_core/pose_library/gui.py
index b4142f8c4c1..9f271b24530 100644
--- a/scripts/addons_core/pose_library/gui.py
+++ b/scripts/addons_core/pose_library/gui.py
@@ -15,7 +15,7 @@ from bpy.types import (
     UILayout,
     UIList,
 )
-from bl_ui_utils.layout import operator_context
+from _bl_ui_utils.layout import operator_context
 
 
 class VIEW3D_MT_pose_modify(Menu):
diff --git a/scripts/addons_core/ui_translate/settings.py b/scripts/addons_core/ui_translate/settings.py
index a88ad7eb372..97a92505db6 100644
--- a/scripts/addons_core/ui_translate/settings.py
+++ b/scripts/addons_core/ui_translate/settings.py
@@ -17,7 +17,7 @@ else:
         BoolProperty,
         StringProperty,
     )
-    from bl_i18n_utils import settings as settings_i18n
+    from _bl_i18n_utils import settings as settings_i18n
 
 
 settings = settings_i18n.I18nSettings()
diff --git a/scripts/addons_core/ui_translate/update_addon.py b/scripts/addons_core/ui_translate/update_addon.py
index 14793747d1a..aff9c37d41d 100644
--- a/scripts/addons_core/ui_translate/update_addon.py
+++ b/scripts/addons_core/ui_translate/update_addon.py
@@ -16,8 +16,8 @@ else:
         StringProperty,
     )
     from . import settings
-    from bl_i18n_utils import utils as utils_i18n
-    from bl_i18n_utils import bl_extract_messages
+    from _bl_i18n_utils import utils as utils_i18n
+    from _bl_i18n_utils import bl_extract_messages
 
 from bpy.app.translations import pgettext_rpt as rpt_
 import addon_utils
diff --git a/scripts/addons_core/ui_translate/update_repo.py b/scripts/addons_core/ui_translate/update_repo.py
index 9c256e47c00..b4be8d0fb8b 100644
--- a/scripts/addons_core/ui_translate/update_repo.py
+++ b/scripts/addons_core/ui_translate/update_repo.py
@@ -15,8 +15,8 @@ else:
         EnumProperty,
     )
     from . import settings
-    from bl_i18n_utils import utils as utils_i18n
-    from bl_i18n_utils import utils_languages_menu
+    from _bl_i18n_utils import utils as utils_i18n
+    from _bl_i18n_utils import utils_languages_menu
 
 import concurrent.futures
 import io
@@ -85,7 +85,7 @@ class UI_OT_i18n_updatetranslation_work_repo(Operator):
         #       This is a problem because spawned processes do not inherit the whole environment
         #       of the current (Blender-customized) python. In practice, the `bpy` module won't load e.g.
         #       So care must be taken that the callback passed to the executor does not rely on any
-        #       Blender-specific modules etc. This is why it is using a class method from `bl_i18n_utils`
+        #       Blender-specific modules etc. This is why it is using a class method from `_bl_i18n_utils`
         #       module, rather than a local function of this current Blender-only module.
         # FIXME: This can easily deadlock on powerful machine with lots of RAM (128GB) and cores (32)...
         # ~ with concurrent.futures.ProcessPoolExecutor() as exctr:
diff --git a/scripts/addons_core/ui_translate/update_ui.py b/scripts/addons_core/ui_translate/update_ui.py
index 774bb48ac4d..dc45726df2c 100644
--- a/scripts/addons_core/ui_translate/update_ui.py
+++ b/scripts/addons_core/ui_translate/update_ui.py
@@ -23,7 +23,7 @@ else:
         CollectionProperty,
     )
     from . import settings
-    from bl_i18n_utils import utils as utils_i18n
+    from _bl_i18n_utils import utils as utils_i18n
 
 from bpy.app.translations import pgettext_iface as iface_
 
diff --git a/scripts/modules/animsys_refactor.py b/scripts/modules/_animsys_refactor.py
similarity index 100%
rename from scripts/modules/animsys_refactor.py
rename to scripts/modules/_animsys_refactor.py
diff --git a/scripts/modules/bl_console_utils/__init__.py b/scripts/modules/_bl_console_utils/__init__.py
similarity index 100%
rename from scripts/modules/bl_console_utils/__init__.py
rename to scripts/modules/_bl_console_utils/__init__.py
diff --git a/scripts/modules/bl_console_utils/autocomplete/__init__.py b/scripts/modules/_bl_console_utils/autocomplete/__init__.py
similarity index 100%
rename from scripts/modules/bl_console_utils/autocomplete/__init__.py
rename to scripts/modules/_bl_console_utils/autocomplete/__init__.py
diff --git a/scripts/modules/bl_console_utils/autocomplete/complete_calltip.py b/scripts/modules/_bl_console_utils/autocomplete/complete_calltip.py
similarity index 100%
rename from scripts/modules/bl_console_utils/autocomplete/complete_calltip.py
rename to scripts/modules/_bl_console_utils/autocomplete/complete_calltip.py
diff --git a/scripts/modules/bl_console_utils/autocomplete/complete_import.py b/scripts/modules/_bl_console_utils/autocomplete/complete_import.py
similarity index 100%
rename from scripts/modules/bl_console_utils/autocomplete/complete_import.py
rename to scripts/modules/_bl_console_utils/autocomplete/complete_import.py
diff --git a/scripts/modules/bl_console_utils/autocomplete/complete_namespace.py b/scripts/modules/_bl_console_utils/autocomplete/complete_namespace.py
similarity index 100%
rename from scripts/modules/bl_console_utils/autocomplete/complete_namespace.py
rename to scripts/modules/_bl_console_utils/autocomplete/complete_namespace.py
diff --git a/scripts/modules/bl_console_utils/autocomplete/intellisense.py b/scripts/modules/_bl_console_utils/autocomplete/intellisense.py
similarity index 100%
rename from scripts/modules/bl_console_utils/autocomplete/intellisense.py
rename to scripts/modules/_bl_console_utils/autocomplete/intellisense.py
diff --git a/scripts/modules/bl_i18n_utils/__init__.py b/scripts/modules/_bl_i18n_utils/__init__.py
similarity index 100%
rename from scripts/modules/bl_i18n_utils/__init__.py
rename to scripts/modules/_bl_i18n_utils/__init__.py
diff --git a/scripts/modules/bl_i18n_utils/bl_extract_messages.py b/scripts/modules/_bl_i18n_utils/bl_extract_messages.py
similarity index 99%
rename from scripts/modules/bl_i18n_utils/bl_extract_messages.py
rename to scripts/modules/_bl_i18n_utils/bl_extract_messages.py
index 1fdc74927be..f3c34c4018c 100644
--- a/scripts/modules/bl_i18n_utils/bl_extract_messages.py
+++ b/scripts/modules/_bl_i18n_utils/bl_extract_messages.py
@@ -18,7 +18,7 @@ import glob
 from pathlib import PurePath
 
 # XXX Relative import does not work here when used from Blender...
-from bl_i18n_utils import settings as settings_i18n, utils
+from _bl_i18n_utils import settings as settings_i18n, utils
 
 import bpy
 
@@ -31,7 +31,7 @@ filter_message = ignore_reg.match
 
 def init_spell_check(settings, lang="en_US"):
     try:
-        from bl_i18n_utils import utils_spell_check
+        from _bl_i18n_utils import utils_spell_check
         return utils_spell_check.SpellChecker(settings, lang)
     except Exception as ex:
         print("Failed to import utils_spell_check ({})".format(str(ex)))
@@ -1231,7 +1231,7 @@ def dump_messages(do_messages, do_checks, settings):
     # Get strings specific to translations' menu.
     for lng in settings.LANGUAGES:
         process_msg(
-            msgs, settings.DEFAULT_CONTEXT, lng[1], "Languages’ labels from bl_i18n_utils/settings.py",
+            msgs, settings.DEFAULT_CONTEXT, lng[1], "Languages’ labels from _bl_i18n_utils/settings.py",
             reports, None, settings,
         )
 
diff --git a/scripts/modules/bl_i18n_utils/merge_po.py b/scripts/modules/_bl_i18n_utils/merge_po.py
similarity index 100%
rename from scripts/modules/bl_i18n_utils/merge_po.py
rename to scripts/modules/_bl_i18n_utils/merge_po.py
diff --git a/scripts/modules/bl_i18n_utils/settings.py b/scripts/modules/_bl_i18n_utils/settings.py
similarity index 100%
rename from scripts/modules/bl_i18n_utils/settings.py
rename to scripts/modules/_bl_i18n_utils/settings.py
diff --git a/scripts/modules/bl_i18n_utils/settings_user.py b/scripts/modules/_bl_i18n_utils/settings_user.py
similarity index 100%
rename from scripts/modules/bl_i18n_utils/settings_user.py
rename to scripts/modules/_bl_i18n_utils/settings_user.py
diff --git a/scripts/modules/bl_i18n_utils/utils.py b/scripts/modules/_bl_i18n_utils/utils.py
similarity index 99%
rename from scripts/modules/bl_i18n_utils/utils.py
rename to scripts/modules/_bl_i18n_utils/utils.py
index 3741113f797..e18e3e56230 100644
--- a/scripts/modules/bl_i18n_utils/utils.py
+++ b/scripts/modules/_bl_i18n_utils/utils.py
@@ -22,7 +22,7 @@ import struct
 import tempfile
 import time
 
-from bl_i18n_utils import (
+from _bl_i18n_utils import (
     settings,
     utils_rtl,
 )
diff --git a/scripts/modules/bl_i18n_utils/utils_cli.py b/scripts/modules/_bl_i18n_utils/utils_cli.py
similarity index 100%
rename from scripts/modules/bl_i18n_utils/utils_cli.py
rename to scripts/modules/_bl_i18n_utils/utils_cli.py
diff --git a/scripts/modules/bl_i18n_utils/utils_languages_menu.py b/scripts/modules/_bl_i18n_utils/utils_languages_menu.py
similarity index 96%
rename from scripts/modules/bl_i18n_utils/utils_languages_menu.py
rename to scripts/modules/_bl_i18n_utils/utils_languages_menu.py
index c8c20cdc330..e1e7f1c389d 100755
--- a/scripts/modules/bl_i18n_utils/utils_languages_menu.py
+++ b/scripts/modules/_bl_i18n_utils/utils_languages_menu.py
@@ -56,7 +56,7 @@ def gen_menu_file(stats, settings):
         "# ID must be unique, except for 0 value (marks categories for menu).",
         "# Line starting with a # are comments!",
         "#",
-        "# Automatically generated by bl_i18n_utils/utils_languages_menu.py script.",
+        "# Automatically generated by _bl_i18n_utils/utils_languages_menu.py script.",
         "# Highest ID currently in use: {}".format(highest_uid),
     ]
     for uid_num, label, uid, flag, lvl in langs:
diff --git a/scripts/modules/bl_i18n_utils/utils_rtl.py b/scripts/modules/_bl_i18n_utils/utils_rtl.py
similarity index 100%
rename from scripts/modules/bl_i18n_utils/utils_rtl.py
rename to scripts/modules/_bl_i18n_utils/utils_rtl.py
diff --git a/scripts/modules/bl_i18n_utils/utils_spell_check.py b/scripts/modules/_bl_i18n_utils/utils_spell_check.py
similarity index 100%
rename from scripts/modules/bl_i18n_utils/utils_spell_check.py
rename to scripts/modules/_bl_i18n_utils/utils_spell_check.py
diff --git a/scripts/modules/bl_previews_utils/bl_previews_render.py b/scripts/modules/_bl_previews_utils/bl_previews_render.py
similarity index 100%
rename from scripts/modules/bl_previews_utils/bl_previews_render.py
rename to scripts/modules/_bl_previews_utils/bl_previews_render.py
diff --git a/scripts/modules/bl_rna_utils/__init__.py b/scripts/modules/_bl_rna_utils/__init__.py
similarity index 100%
rename from scripts/modules/bl_rna_utils/__init__.py
rename to scripts/modules/_bl_rna_utils/__init__.py
diff --git a/scripts/modules/bl_rna_utils/data_path.py b/scripts/modules/_bl_rna_utils/data_path.py
similarity index 100%
rename from scripts/modules/bl_rna_utils/data_path.py
rename to scripts/modules/_bl_rna_utils/data_path.py
diff --git a/scripts/modules/bl_text_utils/__init__.py b/scripts/modules/_bl_text_utils/__init__.py
similarity index 100%
rename from scripts/modules/bl_text_utils/__init__.py
rename to scripts/modules/_bl_text_utils/__init__.py
diff --git a/scripts/modules/bl_text_utils/external_editor.py b/scripts/modules/_bl_text_utils/external_editor.py
similarity index 100%
rename from scripts/modules/bl_text_utils/external_editor.py
rename to scripts/modules/_bl_text_utils/external_editor.py
diff --git a/scripts/modules/bl_ui_utils/__init__.py b/scripts/modules/_bl_ui_utils/__init__.py
similarity index 100%
rename from scripts/modules/bl_ui_utils/__init__.py
rename to scripts/modules/_bl_ui_utils/__init__.py
diff --git a/scripts/modules/bl_ui_utils/layout.py b/scripts/modules/_bl_ui_utils/layout.py
similarity index 100%
rename from scripts/modules/bl_ui_utils/layout.py
rename to scripts/modules/_bl_ui_utils/layout.py
diff --git a/scripts/modules/bpy_restrict_state.py b/scripts/modules/_bpy_restrict_state.py
similarity index 100%
rename from scripts/modules/bpy_restrict_state.py
rename to scripts/modules/_bpy_restrict_state.py
diff --git a/scripts/modules/console_python.py b/scripts/modules/_console_python.py
similarity index 99%
rename from scripts/modules/console_python.py
rename to scripts/modules/_console_python.py
index 18ce6915909..097be2d8544 100644
--- a/scripts/modules/console_python.py
+++ b/scripts/modules/_console_python.py
@@ -237,7 +237,7 @@ execute.hooks = []
 
 
 def autocomplete(context):
-    from bl_console_utils.autocomplete import intellisense
+    from _bl_console_utils.autocomplete import intellisense
 
     sc = context.space_data
 
diff --git a/scripts/modules/console_shell.py b/scripts/modules/_console_shell.py
similarity index 100%
rename from scripts/modules/console_shell.py
rename to scripts/modules/_console_shell.py
diff --git a/scripts/modules/graphviz_export.py b/scripts/modules/_graphviz_export.py
similarity index 100%
rename from scripts/modules/graphviz_export.py
rename to scripts/modules/_graphviz_export.py
diff --git a/scripts/modules/keyingsets_utils.py b/scripts/modules/_keyingsets_utils.py
similarity index 100%
rename from scripts/modules/keyingsets_utils.py
rename to scripts/modules/_keyingsets_utils.py
diff --git a/scripts/modules/rna_info.py b/scripts/modules/_rna_info.py
similarity index 100%
rename from scripts/modules/rna_info.py
rename to scripts/modules/_rna_info.py
diff --git a/scripts/modules/rna_manual_reference.py b/scripts/modules/_rna_manual_reference.py
similarity index 100%
rename from scripts/modules/rna_manual_reference.py
rename to scripts/modules/_rna_manual_reference.py
diff --git a/scripts/modules/rna_xml.py b/scripts/modules/_rna_xml.py
similarity index 100%
rename from scripts/modules/rna_xml.py
rename to scripts/modules/_rna_xml.py
diff --git a/scripts/modules/addon_utils.py b/scripts/modules/addon_utils.py
index 4c6cfc49657..b41b43eafea 100644
--- a/scripts/modules/addon_utils.py
+++ b/scripts/modules/addon_utils.py
@@ -332,7 +332,7 @@ def enable(module_name, *, default_set=False, persistent=False, refresh_handled=
     import os
     import sys
     import importlib
-    from bpy_restrict_state import RestrictBlend
+    from _bpy_restrict_state import RestrictBlend
 
     if handle_error is None:
         def handle_error(ex):
diff --git a/scripts/modules/bl_app_template_utils.py b/scripts/modules/bl_app_template_utils.py
index eccca8c1463..f1c8459b95e 100644
--- a/scripts/modules/bl_app_template_utils.py
+++ b/scripts/modules/bl_app_template_utils.py
@@ -35,7 +35,7 @@ _modules = {}
 
 
 def _enable(template_id, *, handle_error=None, ignore_not_found=False):
-    from bpy_restrict_state import RestrictBlend
+    from _bpy_restrict_state import RestrictBlend
 
     if handle_error is None:
         def handle_error(_ex):
diff --git a/scripts/modules/bpy/utils/__init__.py b/scripts/modules/bpy/utils/__init__.py
index bf9b4898431..0c8b3837d23 100644
--- a/scripts/modules/bpy/utils/__init__.py
+++ b/scripts/modules/bpy/utils/__init__.py
@@ -321,7 +321,7 @@ def load_scripts(*, reload_scripts=False, refresh_scripts=False, extensions=True
         # Without this, add-on register functions accessing key-map properties can crash, see: #111702.
         _bpy.context.window_manager.keyconfigs.update(keep_properties=True)
 
-    from bpy_restrict_state import RestrictBlend
+    from _bpy_restrict_state import RestrictBlend
 
     with RestrictBlend():
         for base_path in script_paths(use_user=use_user):
@@ -367,7 +367,7 @@ def _on_exit():
 
     # Call `unregister` function on internal startup module.
     # Must only be used as part of Blender 'exit' process.
-    from bpy_restrict_state import RestrictBlend
+    from _bpy_restrict_state import RestrictBlend
     with RestrictBlend():
         for mod_name in reversed(_registered_module_names):
             if (mod := _sys.modules.get(mod_name)) is None:
@@ -1231,7 +1231,7 @@ def _blender_default_map():
     # NOTE(@ideasman42): Avoid importing this as there is no need to keep the lookup table in memory.
     # As this runs when the user accesses the "Online Manual", the overhead loading the file is acceptable.
     # In my tests it's under 1/100th of a second loading from a `pyc`.
-    ref_mod = execfile(_os.path.join(_script_base_dir, "modules", "rna_manual_reference.py"))
+    ref_mod = execfile(_os.path.join(_script_base_dir, "modules", "_rna_manual_reference.py"))
     return (ref_mod.url_manual_prefix, ref_mod.url_manual_mapping)
 
 
diff --git a/scripts/startup/bl_operators/anim.py b/scripts/startup/bl_operators/anim.py
index f102e243f49..da45a2224d9 100644
--- a/scripts/startup/bl_operators/anim.py
+++ b/scripts/startup/bl_operators/anim.py
@@ -398,7 +398,7 @@ class UpdateAnimatedTransformConstraint(Operator):
     )
 
     def execute(self, context):
-        import animsys_refactor
+        import _animsys_refactor as animsys_refactor
         from math import radians
         import io
 
diff --git a/scripts/startup/bl_operators/console.py b/scripts/startup/bl_operators/console.py
index b892bef0539..07d6085e64d 100644
--- a/scripts/startup/bl_operators/console.py
+++ b/scripts/startup/bl_operators/console.py
@@ -15,7 +15,7 @@ from bpy.app.translations import contexts as i18n_contexts
 
 def _lang_module_get(sc):
     return __import__(
-        "console_" + sc.language,
+        "_console_" + sc.language,
         # for python 3.3, maybe a bug???
         level=0,
     )
diff --git a/scripts/startup/bl_operators/file.py b/scripts/startup/bl_operators/file.py
index 51ed5414d1b..8e4ece1156a 100644
--- a/scripts/startup/bl_operators/file.py
+++ b/scripts/startup/bl_operators/file.py
@@ -95,7 +95,7 @@ class WM_OT_previews_batch_generate(Operator):
     def execute(self, context):
         import os
         import subprocess
-        from bl_previews_utils import bl_previews_render as preview_render
+        from _bl_previews_utils import bl_previews_render as preview_render
 
         context.window_manager.progress_begin(0, len(self.files))
         context.window_manager.progress_update(0)
@@ -204,7 +204,7 @@ class WM_OT_previews_batch_clear(Operator):
     def execute(self, context):
         import os
         import subprocess
-        from bl_previews_utils import bl_previews_render as preview_render
+        from _bl_previews_utils import bl_previews_render as preview_render
 
         context.window_manager.progress_begin(0, len(self.files))
         context.window_manager.progress_update(0)
diff --git a/scripts/startup/bl_operators/presets.py b/scripts/startup/bl_operators/presets.py
index eaf7db5287e..a3ae20e4baa 100644
--- a/scripts/startup/bl_operators/presets.py
+++ b/scripts/startup/bl_operators/presets.py
@@ -164,7 +164,7 @@ class AddPresetBase:
                 print("Writing Preset: {!r}".format(filepath))
 
                 if is_xml:
-                    import rna_xml
+                    import _rna_xml as rna_xml
                     rna_xml.xml_file_write(context, filepath, preset_menu_class.preset_xml_map)
                 else:
 
@@ -304,7 +304,7 @@ class ExecutePreset(Operator):
                 self.report({'ERROR'}, "Failed to execute the preset: " + repr(ex))
 
         elif ext == ".xml":
-            import rna_xml
+            import _rna_xml as rna_xml
             preset_xml_map = preset_class.preset_xml_map
             preset_xml_secure_types = getattr(preset_class, "preset_xml_secure_types", None)
 
@@ -708,7 +708,7 @@ class SavePresetInterfaceTheme(AddPresetBase, Operator):
     # while redrawing as it may involve remote file-system access.
 
     def execute(self, context):
-        import rna_xml
+        import _rna_xml as rna_xml
         filepath = context.preferences.themes[0].filepath
         if (not filepath) or _is_path_readonly(filepath):
             self.report({'ERROR'}, "Built-in themes cannot be overwritten")
diff --git a/scripts/startup/bl_operators/wm.py b/scripts/startup/bl_operators/wm.py
index 235842838b1..0a08c084248 100644
--- a/scripts/startup/bl_operators/wm.py
+++ b/scripts/startup/bl_operators/wm.py
@@ -31,7 +31,7 @@ from bpy.app.translations import (
 
 def _rna_path_prop_search_for_context_impl(context, edit_text, unique_attrs):
     # Use the same logic as auto-completing in the Python console to expand the data-path.
-    from bl_console_utils.autocomplete import intellisense
+    from _bl_console_utils.autocomplete import intellisense
     context_prefix = "context."
     line = context_prefix + edit_text
     cursor = len(line)
@@ -148,7 +148,7 @@ def context_path_validate(context, data_path):
 
 
 def context_path_to_rna_property(context, data_path):
-    from bl_rna_utils.data_path import property_definition_from_data_path
+    from _bl_rna_utils.data_path import property_definition_from_data_path
     rna_prop = property_definition_from_data_path(context, "." + data_path)
     if rna_prop is not None:
         return rna_prop
@@ -167,7 +167,7 @@ def context_path_decompose(data_path):
     # Note that the `.` is removed from the start of the first and second values,
     # this is done because `.attr` isn't convenient to use as an argument,
     # also the convention is not to include this within the data paths or the operator logic for `bpy.ops.wm.*`.
-    from bl_rna_utils.data_path import decompose_data_path
+    from _bl_rna_utils.data_path import decompose_data_path
     path_split = decompose_data_path("." + data_path)
 
     # Find the last property that isn't a function call.
@@ -1342,7 +1342,7 @@ class WM_OT_doc_view_manual(Operator):
             self.report(
                 {'WARNING'},
                 rpt_("No reference available {!r}, "
-                     "Update info in 'rna_manual_reference.py' "
+                     "Update info in '_rna_manual_reference.py' "
                      "or callback to bpy.utils.manual_map()").format(self.doc_id)
             )
             return {'CANCELLED'}
diff --git a/scripts/startup/bl_ui/space_graph.py b/scripts/startup/bl_ui/space_graph.py
index f31b3ae26f4..12daf07df5b 100644
--- a/scripts/startup/bl_ui/space_graph.py
+++ b/scripts/startup/bl_ui/space_graph.py
@@ -384,7 +384,7 @@ class GRAPH_MT_key_density(Menu):
     bl_label = "Density"
 
     def draw(self, _context):
-        from bl_ui_utils.layout import operator_context
+        from _bl_ui_utils.layout import operator_context
         layout = self.layout
         layout.operator("graph.decimate", text="Decimate (Ratio)").mode = 'RATIO'
         # Using the modal operation doesn't make sense for this variant
diff --git a/scripts/startup/bl_ui/space_sequencer.py b/scripts/startup/bl_ui/space_sequencer.py
index a43c1658500..702fdac4e44 100644
--- a/scripts/startup/bl_ui/space_sequencer.py
+++ b/scripts/startup/bl_ui/space_sequencer.py
@@ -1075,7 +1075,7 @@ class SEQUENCER_MT_strip(Menu):
     bl_label = "Strip"
 
     def draw(self, context):
-        from bl_ui_utils.layout import operator_context
+        from _bl_ui_utils.layout import operator_context
 
         layout = self.layout
         st = context.space_data
diff --git a/scripts/startup/bl_ui/space_topbar.py b/scripts/startup/bl_ui/space_topbar.py
index f9d73b51075..726b9ef8b25 100644
--- a/scripts/startup/bl_ui/space_topbar.py
+++ b/scripts/startup/bl_ui/space_topbar.py
@@ -553,7 +553,7 @@ class TOPBAR_MT_window(Menu):
 
     def draw(self, context):
         import sys
-        from bl_ui_utils.layout import operator_context
+        from _bl_ui_utils.layout import operator_context
 
         layout = self.layout
 
diff --git a/scripts/startup/bl_ui/space_view3d.py b/scripts/startup/bl_ui/space_view3d.py
index 048e5ced9c2..5c83c1a3744 100644
--- a/scripts/startup/bl_ui/space_view3d.py
+++ b/scripts/startup/bl_ui/space_view3d.py
@@ -3212,7 +3212,7 @@ class VIEW3D_MT_object_parent(Menu):
     bl_translation_context = i18n_contexts.operator_default
 
     def draw(self, _context):
-        from bl_ui_utils.layout import operator_context
+        from _bl_ui_utils.layout import operator_context
 
         layout = self.layout
 
diff --git a/scripts/startup/keyingsets_builtins.py b/scripts/startup/keyingsets_builtins.py
index 77c1937eede..e63200f9543 100644
--- a/scripts/startup/keyingsets_builtins.py
+++ b/scripts/startup/keyingsets_builtins.py
@@ -15,7 +15,7 @@ are supported.
 """
 
 import bpy
-import keyingsets_utils
+import _keyingsets_utils as keyingsets_utils
 from bpy.types import KeyingSetInfo
 
 ###############################
diff --git a/source/blender/editors/space_text/text_ops.cc b/source/blender/editors/space_text/text_ops.cc
index 47376c3a80b..dddbbc92d22 100644
--- a/source/blender/editors/space_text/text_ops.cc
+++ b/source/blender/editors/space_text/text_ops.cc
@@ -3985,11 +3985,11 @@ static bool text_jump_to_file_at_point_external(bContext *C,
   err_info.reports = reports;
   err_info.report_prefix = "External editor";
 
-  const char *expr_imports[] = {"bl_text_utils", "bl_text_utils.external_editor", "os", nullptr};
+  const char *expr_imports[] = {"_bl_text_utils", "_bl_text_utils.external_editor", "os", nullptr};
   std::string expr;
   {
     std::stringstream expr_stream;
-    expr_stream << "bl_text_utils.external_editor.open_external_editor(os.fsdecode(b'";
+    expr_stream << "_bl_text_utils.external_editor.open_external_editor(os.fsdecode(b'";
     for (const char *ch = filepath; *ch; ch++) {
       expr_stream << "\\x" << std::hex << int(*ch);
     }
diff --git a/source/blender/makesrna/rna_cleanup/rna_cleaner.py b/source/blender/makesrna/rna_cleanup/rna_cleaner.py
index 3c7a57bbe39..368b64740f4 100755
--- a/source/blender/makesrna/rna_cleanup/rna_cleaner.py
+++ b/source/blender/makesrna/rna_cleanup/rna_cleaner.py
@@ -11,7 +11,7 @@ Typical line in the input file (elements in [] are optional).
 [comment *] ToolSettings.snap_align_rotation -> use_snap_align_rotation:    boolean    [Align description]
 
 Geterate output format from blender run this:
- ./blender.bin --background --python ./scripts/modules/rna_info.py 2> source/blender/makesrna/rna_cleanup/out.txt
+ ./blender.bin --background --python ./scripts/modules/_rna_info.py 2> source/blender/makesrna/rna_cleanup/out.txt
 """
 
 
diff --git a/tests/python/bl_load_py_modules.py b/tests/python/bl_load_py_modules.py
index 7119f7fa565..7aaa4f14fac 100644
--- a/tests/python/bl_load_py_modules.py
+++ b/tests/python/bl_load_py_modules.py
@@ -18,8 +18,8 @@ import os
 # The trailing components of the path are used instead of the module name.
 # Both script files & directories are supported which prevents searching inside the directory.
 EXCLUDE_MODULE_PATHS = {
-    "bl_i18n_utils",
-    "bl_previews_utils",
+    "_bl_i18n_utils",
+    "_bl_previews_utils",
     "cycles",
 
     # These tests which run stand-alone and aren't imported as modules.
diff --git a/tests/python/bl_rna_manual_reference.py b/tests/python/bl_rna_manual_reference.py
index bf9cfca4de3..5ce0c42a340 100644
--- a/tests/python/bl_rna_manual_reference.py
+++ b/tests/python/bl_rna_manual_reference.py
@@ -17,7 +17,7 @@ VERBOSE = False
 
 
 def test_data():
-    import rna_manual_reference
+    import _rna_manual_reference as rna_manual_reference
 
     assert isinstance(rna_manual_reference.url_manual_mapping, tuple)
     for i, value in enumerate(rna_manual_reference.url_manual_mapping):
@@ -37,7 +37,7 @@ def lookup_rna_url(rna_id, visit_indices):
     A local version of ``WM_OT_doc_view_manual._lookup_rna_url``
     that tracks which matches are found.
     """
-    import rna_manual_reference
+    import _rna_manual_reference as rna_manual_reference
     from fnmatch import fnmatchcase
     rna_id = rna_id.lower()
     for i, (pattern, url_suffix) in enumerate(rna_manual_reference.url_manual_mapping):
@@ -51,7 +51,7 @@ def lookup_rna_url(rna_id, visit_indices):
 def test_lookup_coverage():
 
     def rna_ids():
-        import rna_info
+        import _rna_info as rna_info
         struct = rna_info.BuildRNAInfo()[0]
         for struct_id, v in sorted(struct.items()):
             props = [(prop.identifier, prop) for prop in v.properties]
@@ -96,7 +96,7 @@ def test_lookup_coverage():
     print("---------------------------------------")
     print("Unused RNA Patterns Known to the Manual")
 
-    import rna_manual_reference
+    import _rna_manual_reference as rna_manual_reference
     for i, (pattern, url_suffix) in enumerate(rna_manual_reference.url_manual_mapping):
         if i not in visit_indices:
             print(pattern, url_suffix)
@@ -118,7 +118,7 @@ def test_language_coverage():
 def test_urls():
     import os
     import sys
-    import rna_manual_reference
+    import _rna_manual_reference as rna_manual_reference
 
     import urllib.error
     from urllib.request import urlopen
diff --git a/tests/python/rna_info_dump.py b/tests/python/rna_info_dump.py
index 2d1482a8c45..d6eb2c0b12f 100644
--- a/tests/python/rna_info_dump.py
+++ b/tests/python/rna_info_dump.py
@@ -97,7 +97,7 @@ def api_dump(use_properties=True, use_functions=True):
         data.insert(0, "# * properties *")
         return data
 
-    import rna_info
+    import _rna_info as rna_info
     struct = rna_info.BuildRNAInfo()[0]
     data = []
 
diff --git a/tools/check_source/check_descriptions.py b/tools/check_source/check_descriptions.py
index 10aacd3a9d1..0539283610d 100644
--- a/tools/check_source/check_descriptions.py
+++ b/tools/check_source/check_descriptions.py
@@ -92,7 +92,7 @@ DUPLICATE_IGNORE = {
 
 
 def check_duplicates():
-    import rna_info
+    import _rna_info as rna_info
 
     DUPLICATE_IGNORE_FOUND = set()
     DUPLICATE_ACCEPT_FOUND = set()
diff --git a/tools/check_source/check_spelling_config.py b/tools/check_source/check_spelling_config.py
index b10bce92926..3303d62837c 100644
--- a/tools/check_source/check_spelling_config.py
+++ b/tools/check_source/check_spelling_config.py
@@ -907,7 +907,7 @@ dict_ignore_hyphenated_suffix = {
 }
 
 files_ignore = {
-    "scripts/modules/bl_i18n_utils/utils_spell_check.py",  # UI spelling, doesn't always match code spelling.
+    "scripts/modules/_bl_i18n_utils/utils_spell_check.py",  # UI spelling, doesn't always match code spelling.
     "tools/utils/git_data_canonical_authors.py",  # Too many names which aren't in the dictionary.
     "tools/utils_doc/rna_manual_reference_updater.py",  # Contains language ID references.
 
diff --git a/tools/utils/autopep8_clean_config.py b/tools/utils/autopep8_clean_config.py
index 5cb04c180cb..a1cb6016865 100644
--- a/tools/utils/autopep8_clean_config.py
+++ b/tools/utils/autopep8_clean_config.py
@@ -40,6 +40,6 @@ PATHS_EXCLUDE: set[str] = set(
         "tools/svn_rev_map/sha1_to_rev.py",
         "tools/svn_rev_map/rev_to_sha1.py",
         "tools/svn_rev_map/rev_to_sha1.py",
-        "scripts/modules/rna_manual_reference.py",
+        "scripts/modules/_rna_manual_reference.py",
     )
 )
diff --git a/tools/utils_doc/rna_manual_reference_updater.py b/tools/utils_doc/rna_manual_reference_updater.py
index a2c963ad00a..82c83f8683f 100644
--- a/tools/utils_doc/rna_manual_reference_updater.py
+++ b/tools/utils_doc/rna_manual_reference_updater.py
@@ -142,7 +142,7 @@ def main():
     parser.add_argument(
         "--output",
         dest="output",
-        default=os.path.join(BASE_DIR, "scripts", "modules", "rna_manual_reference.py"),
+        default=os.path.join(BASE_DIR, "scripts", "modules", "_rna_manual_reference.py"),
         required=False,
         help="path to output including filename and extentsion",
         metavar="FILE")
diff --git a/tools/utils_maintenance/autopep8_format_paths.py b/tools/utils_maintenance/autopep8_format_paths.py
index d0a9e0e0361..cdd7005317e 100755
--- a/tools/utils_maintenance/autopep8_format_paths.py
+++ b/tools/utils_maintenance/autopep8_format_paths.py
@@ -46,7 +46,7 @@ extensions = (
 )
 
 ignore_files = {
-    "scripts/modules/rna_manual_reference.py",  # Large generated file, don't format.
+    "scripts/modules/_rna_manual_reference.py",  # Large generated file, don't format.
     "tools/svn_rev_map/rev_to_sha1.py",
     "tools/svn_rev_map/sha1_to_rev.py",
 }
diff --git a/tools/utils_maintenance/blender_update_themes.py b/tools/utils_maintenance/blender_update_themes.py
index 4c5229c35b1..3fcef656809 100644
--- a/tools/utils_maintenance/blender_update_themes.py
+++ b/tools/utils_maintenance/blender_update_themes.py
@@ -15,7 +15,7 @@ import os
 
 
 def update(filepath):
-    import rna_xml
+    import _rna_xml as rna_xml
     context = bpy.context
 
     print("Updating theme: {!r}".format(filepath))