diff --git a/CHANGES/12996.bugfix.rst b/CHANGES/12996.bugfix.rst
new file mode 100644
index 00000000000..c43d973fb77
--- /dev/null
+++ b/CHANGES/12996.bugfix.rst
@@ -0,0 +1,5 @@
+Fixed ``parse_content_disposition`` rejecting otherwise-valid
+``Content-Disposition`` header values that contain optional whitespace (OWS)
+around the disposition type (e.g. ``"form-data ; name=\"field\""``).
+The disposition type is now stripped before token validation, consistent with
+how parameter keys are already handled -- by :user:`JSap0914`.
diff --git a/aiohttp/multipart.py b/aiohttp/multipart.py
index 7e63e324779..190f2e2b4cc 100644
--- a/aiohttp/multipart.py
+++ b/aiohttp/multipart.py
@@ -102,7 +102,9 @@ def unescape(text: str, *, chars: str = "".join(map(re.escape, CHAR))) -> str:
     if not header:
         return None, {}
 
+    # https://www.rfc-editor.org/info/rfc9110/#section-5.6.6-2
     disptype, *parts = header.split(";")
+    disptype = disptype.strip()
     if not is_token(disptype):
         warnings.warn(BadContentDispositionHeader(header))
         return None, {}
diff --git a/tests/test_multipart_helpers.py b/tests/test_multipart_helpers.py
index 3548feacd40..67bbc86c223 100644
--- a/tests/test_multipart_helpers.py
+++ b/tests/test_multipart_helpers.py
@@ -659,6 +659,16 @@ def test_empty_param_value_multiple(self) -> None:
         assert disptype is None
         assert {} == params
 
+    def test_disptype_with_trailing_space_before_semicolon(self) -> None:
+        disptype, params = parse_content_disposition('form-data ; name="field"')
+        assert disptype == "form-data"
+        assert params == {"name": "field"}
+
+    def test_disptype_with_trailing_space_no_params(self) -> None:
+        disptype, params = parse_content_disposition("inline ")
+        assert disptype == "inline"
+        assert params == {}
+
 
 class TestContentDispositionFilename:
     # http://greenbytes.de/tech/tc2231/