diff --git a/news/12322.bugfix.rst b/news/12322.bugfix.rst
new file mode 100644
index 00000000000..928df878978
--- /dev/null
+++ b/news/12322.bugfix.rst
@@ -0,0 +1 @@
+Improve performance ~17% when installing many wheels offline
diff --git a/src/pip/_internal/utils/urls.py b/src/pip/_internal/utils/urls.py
index 6ba2e04f350..0cbe8ea96e9 100644
--- a/src/pip/_internal/utils/urls.py
+++ b/src/pip/_internal/utils/urls.py
@@ -2,6 +2,7 @@
 import string
 import urllib.parse
 import urllib.request
+from functools import lru_cache
 from typing import Optional
 
 from .compat import WINDOWS
@@ -13,13 +14,22 @@ def get_url_scheme(url: str) -> Optional[str]:
     return url.split(":", 1)[0].lower()
 
 
+@lru_cache(maxsize=None)
+def _normalized_abs_path_to_url(abs_path: str) -> str:
+    """
+    Convert a normalized absolute path to a file: URL.
+    """
+    url = urllib.parse.urljoin("file:", urllib.request.pathname2url(abs_path))
+    return url
+
+
 def path_to_url(path: str) -> str:
     """
     Convert a path to a file: URL.  The path will be made absolute and have
     quoted path parts.
     """
     path = os.path.normpath(os.path.abspath(path))
-    url = urllib.parse.urljoin("file:", urllib.request.pathname2url(path))
+    url = _normalized_abs_path_to_url(path)
     return url