diff --git a/Doc/whatsnew/3.15.rst b/Doc/whatsnew/3.15.rst
index d5b14216770906..627bb808816d19 100644
--- a/Doc/whatsnew/3.15.rst
+++ b/Doc/whatsnew/3.15.rst
@@ -828,6 +828,7 @@ mimetypes
 * Add ``application/sql`` and ``application/vnd.sqlite3``.
   (Contributed by Charlie Lin in :gh:`145698`.)
 * Add ``image/jxl``. (Contributed by Foolbar in :gh:`144213`.)
+* Add ``application/efi``. (Contributed by Charlie Lin in :gh:`145720`.)
 * Add the following MIME types:
 
   - ``application/vnd.ms-cab-compressed`` for ``.cab`` extension
diff --git a/Lib/mimetypes.py b/Lib/mimetypes.py
index 60e8c2be1e2504..a834826114614d 100644
--- a/Lib/mimetypes.py
+++ b/Lib/mimetypes.py
@@ -478,6 +478,7 @@ def _default_mime_types():
         '.js'     : 'text/javascript',
         '.mjs'    : 'text/javascript',
         '.dcm'    : 'application/dicom',
+        '.efi'    : 'application/efi',
         '.epub'   : 'application/epub+zip',
         '.gz'     : 'application/gzip',
         '.json'   : 'application/json',
diff --git a/Lib/test/test_mimetypes.py b/Lib/test/test_mimetypes.py
index 2d618081521e10..fffcd36861dcf2 100644
--- a/Lib/test/test_mimetypes.py
+++ b/Lib/test/test_mimetypes.py
@@ -227,6 +227,7 @@ def check_extensions():
                 ("application/epub+zip", ".epub"),
                 ("application/octet-stream", ".bin"),
                 ("application/dicom", ".dcm"),
+                ("application/efi", ".efi"),
                 ("application/gzip", ".gz"),
                 ("application/ogg", ".ogx"),
                 ("application/pdf", ".pdf"),
diff --git a/Misc/NEWS.d/next/Library/2026-03-10-01-54-34.gh-issue-145719.okJRoK.rst b/Misc/NEWS.d/next/Library/2026-03-10-01-54-34.gh-issue-145719.okJRoK.rst
new file mode 100644
index 00000000000000..b7e82a45675614
--- /dev/null
+++ b/Misc/NEWS.d/next/Library/2026-03-10-01-54-34.gh-issue-145719.okJRoK.rst
@@ -0,0 +1 @@
+Add ``application/efi`` MIME type to :mod:`mimetypes`.