diff --git a/Doc/whatsnew/3.16.rst b/Doc/whatsnew/3.16.rst
index e8c75d2f571061a..800f0b7e70b5f31 100644
--- a/Doc/whatsnew/3.16.rst
+++ b/Doc/whatsnew/3.16.rst
@@ -510,6 +510,8 @@ mimetypes
 * Valid extensions start with a '.' or are empty for
   :meth:`mimetypes.MimeTypes.add_type`.
   Undotted extensions now raise a :exc:`ValueError`.
+* Add more MIME types.
+  (Contributed by Charlie Lin in :gh:`146341`.)
 
 shutil
 ------
diff --git a/Lib/mimetypes.py b/Lib/mimetypes.py
index 4339ef5a61397dd..985b12dd0415d8f 100644
--- a/Lib/mimetypes.py
+++ b/Lib/mimetypes.py
@@ -585,10 +585,6 @@ def _default_mime_types():
         '.yaml'   : 'application/yaml',
         '.yml'    : 'application/yaml',
         '.zip'    : 'application/zip',
-        '.3gp'    : 'audio/3gpp',
-        '.3gpp'   : 'audio/3gpp',
-        '.3g2'    : 'audio/3gpp2',
-        '.3gpp2'  : 'audio/3gpp2',
         '.aac'    : 'audio/aac',
         '.adts'   : 'audio/aac',
         '.loas'   : 'audio/aac',
@@ -681,8 +677,15 @@ def _default_mime_types():
         '.sgml'   : 'text/x-sgml',
         '.vcf'    : 'text/x-vcard',
         '.xml'    : 'text/xml',
+        '.3gp'    : 'video/3gpp',
+        '.3gpp'   : 'video/3gpp',
+        '.3g2'    : 'video/3gpp2',
+        '.3gpp2'  : 'video/3gpp2',
+        '.m4s'    : 'video/iso.segment',
+        '.lot'    : 'video/lottie+json',
         '.mkv'    : 'video/matroska',
         '.mk3d'   : 'video/matroska-3d',
+        '.mj2'    : 'video/mj2',
         '.mp4'    : 'video/mp4',
         '.mpeg'   : 'video/mpeg',
         '.m1v'    : 'video/mpeg',
@@ -692,6 +695,12 @@ def _default_mime_types():
         '.ogv'    : 'video/ogg',
         '.mov'    : 'video/quicktime',
         '.qt'     : 'video/quicktime',
+        '.pyv'    : 'video/vnd.ms-playready.media.pyv',
+        '.bik'    : 'video/vnd.radgamettools.bink',
+        '.bk2'    : 'video/vnd.radgamettools.bink',
+        '.sswf'   : 'video/vnd.sealed.swf',
+        '.ssw'    : 'video/vnd.sealed.swf',
+        '.yt'     : 'video/vnd.youtube.yt',
         '.webm'   : 'video/webm',
         '.avi'    : 'video/vnd.avi',
         '.m4v'    : 'video/x-m4v',
diff --git a/Misc/NEWS.d/next/Library/2026-03-23-20-14-57.gh-issue-146341.JSTJlL.rst b/Misc/NEWS.d/next/Library/2026-03-23-20-14-57.gh-issue-146341.JSTJlL.rst
new file mode 100644
index 000000000000000..db3ee1294908483
--- /dev/null
+++ b/Misc/NEWS.d/next/Library/2026-03-23-20-14-57.gh-issue-146341.JSTJlL.rst
@@ -0,0 +1,13 @@
+Add the following MIME types corresponding to file extensions:
+
+``.3gp``   for ``video/3gpp``
+``.3g2``   for ``video/3gpp2``
+``.m4s``   for ``video/iso.segment``
+``.lot``   for ``video/lottie+json``
+``.mj2``   for ``video/mj2``
+``.pyv``   for ``video/vnd.ms-playready.media.pyv``
+``.blk`` and ``.bk2`` for ``video/vnd.radgamettools.bink``
+``.sswf`` and ``.ssw`` for ``video/vnd.sealed.swf``
+``.yt``    for ``video/vnd.youtube.yt``
+
+(Contributed by Charlie Lin in :gh:`146342`.)