diff --git a/Doc/whatsnew/3.15.rst b/Doc/whatsnew/3.15.rst
index 8503a4c7f973fc..23679717122251 100644
--- a/Doc/whatsnew/3.15.rst
+++ b/Doc/whatsnew/3.15.rst
@@ -695,6 +695,20 @@ mimetypes
 * Add ``application/toml``. (Contributed by Gil Forcada in :gh:`139959`.)
 * Rename ``application/x-texinfo`` to ``application/texinfo``.
   (Contributed by Charlie Lin in :gh:`140165`)
+* Add the following:
+   - ``application/efi``
+   - ``application/pem-certificate-chain``
+   - ``application/pgp-keys``
+   - ``application/sql``
+   - ``application/zstd``
+   - ``application/ocsp-request``
+   - ``application/ocsp-response``
+   - ``application/mathematica``
+   - ``application/mathml+xml``
+   - ``application/mbox``
+   - ``application/pem-certificate-chain``
+
+ (Contributed by Charlie Lin in :gh:`140393`)
 
 
 pathlib
diff --git a/Lib/mimetypes.py b/Lib/mimetypes.py
index 48a9f430d45262..f7372d8b1341b5 100644
--- a/Lib/mimetypes.py
+++ b/Lib/mimetypes.py
@@ -477,10 +477,16 @@ def _default_mime_types():
     types_map = _types_map_default = {
         '.js'     : 'text/javascript',
         '.mjs'    : 'text/javascript',
+        '.efi'    : 'application/efi',
         '.epub'   : 'application/epub+zip',
         '.gz'     : 'application/gzip',
         '.json'   : 'application/json',
         '.webmanifest': 'application/manifest+json',
+        '.nb'     : 'application/mathematica',
+        '.ma'     : 'application/mathematica',
+        '.mb'     : 'application/mathematica',
+        '.mml'    : 'application/mathml+xml',
+        '.mbox'   : 'application/mbox',
         '.doc'    : 'application/msword',
         '.dot'    : 'application/msword',
         '.wiz'    : 'application/msword',
@@ -493,13 +499,19 @@ def _default_mime_types():
         '.o'      : 'application/octet-stream',
         '.obj'    : 'application/octet-stream',
         '.so'     : 'application/octet-stream',
+        '.ors'    : 'application/ocsp-response',
+        '.orq'    : 'application/ocsp-request',
         '.oda'    : 'application/oda',
         '.ogx'    : 'application/ogg',
         '.pdf'    : 'application/pdf',
+        '.pem'    : 'application/pem-certificate-chain',
+        '.asc'    : 'application/pgp-keys',
         '.p7c'    : 'application/pkcs7-mime',
         '.ps'     : 'application/postscript',
         '.ai'     : 'application/postscript',
         '.eps'    : 'application/postscript',
+        '.rfcxml' : 'application/rfc+xml',
+        '.sql'    : 'application/sql',
         '.texi'   : 'application/texinfo',
         '.texinfo': 'application/texinfo',
         '.toml'   : 'application/toml',
@@ -566,6 +578,7 @@ def _default_mime_types():
         '.yaml'   : 'application/yaml',
         '.yml'    : 'application/yaml',
         '.zip'    : 'application/zip',
+        '.zst'    : 'application/zstd',
         '.3gp'    : 'audio/3gpp',
         '.3gpp'   : 'audio/3gpp',
         '.3g2'    : 'audio/3gpp2',
diff --git a/Lib/test/test_mimetypes.py b/Lib/test/test_mimetypes.py
index 746984ec0ca9df..107c473f490a59 100644
--- a/Lib/test/test_mimetypes.py
+++ b/Lib/test/test_mimetypes.py
@@ -225,11 +225,23 @@ def test_guess_known_extensions(self):
     def test_preferred_extension(self):
         def check_extensions():
             for mime_type, ext in (
+                ('application/efi', '.efi'),
                 ("application/epub+zip", ".epub"),
+                ('application/json', '.json'),
+                ('application/manifest+json', '.webmanifest'),
+                ('application/mathematica', '.nb'),
+                ('application/mathml+xml', '.mml'),
+                ('application/mbox', '.mbox'),
                 ("application/octet-stream", ".bin"),
                 ("application/gzip", ".gz"),
+                ('application/ocsp-response', '.ors'),
+                ('application/ocsp-request', '.orq'),
+                ('application/pem-certificate-chain', '.pem'),
+                ('application/pgp-keys', '.asc'),
                 ("application/ogg", ".ogx"),
                 ("application/postscript", ".ps"),
+                ('application/rfc+xml', '.rfcxml'),
+                ('application/sql', '.sql'),
                 ("application/texinfo", ".texi"),
                 ("application/toml", ".toml"),
                 ("application/vnd.apple.mpegurl", ".m3u"),
@@ -251,6 +263,7 @@ def check_extensions():
                 ("application/x-troff", ".roff"),
                 ("application/xml", ".xsl"),
                 ("application/yaml", ".yaml"),
+                ('application/zstd', '.zst'),
                 ("audio/flac", ".flac"),
                 ("audio/matroska", ".mka"),
                 ("audio/mp4", ".m4a"),
diff --git a/Misc/NEWS.d/next/Library/2025-10-21-16-39-58.gh-issue-140392.ouL6FW.rst b/Misc/NEWS.d/next/Library/2025-10-21-16-39-58.gh-issue-140392.ouL6FW.rst
new file mode 100644
index 00000000000000..b0bebad5bfe35c
--- /dev/null
+++ b/Misc/NEWS.d/next/Library/2025-10-21-16-39-58.gh-issue-140392.ouL6FW.rst
@@ -0,0 +1,12 @@
+:mod:`mimetypes`: Add the following MIME types:
+
+- ``application/efi``
+- ``application/mathematica``
+- ``application/mathml+xml``
+- ``application/mbox``
+- ``application/ocsp-request``
+- ``application/ocsp-response``
+- ``application/pem-certificate-chain``
+- ``application/pgp-keys``
+- ``application/sql``
+- ``application/zstd``