diff --git a/changelog.d/6825.bugfix b/changelog.d/6825.bugfix
new file mode 100644
index 000000000..d3cacd6d9
--- /dev/null
+++ b/changelog.d/6825.bugfix
@@ -0,0 +1 @@
+Allow URL-encoded User IDs on `/_synapse/admin/v2/users/<user_id>[/admin]` endpoints. Thanks to @NHAS for reporting.
\ No newline at end of file
diff --git a/synapse/rest/admin/users.py b/synapse/rest/admin/users.py
index 345574119..f1c4434f5 100644
--- a/synapse/rest/admin/users.py
+++ b/synapse/rest/admin/users.py
@@ -105,7 +105,7 @@ class UsersRestServletV2(RestServlet):
 
 
 class UserRestServletV2(RestServlet):
-    PATTERNS = (re.compile("^/_synapse/admin/v2/users/(?P<user_id>@[^/]+)$"),)
+    PATTERNS = (re.compile("^/_synapse/admin/v2/users/(?P<user_id>[^/]+)$"),)
 
     """Get request to list user details.
     This needs user to have administrator access in Synapse.
@@ -568,7 +568,7 @@ class UserAdminServlet(RestServlet):
                 {}
     """
 
-    PATTERNS = (re.compile("^/_synapse/admin/v1/users/(?P<user_id>@[^/]*)/admin$"),)
+    PATTERNS = (re.compile("^/_synapse/admin/v1/users/(?P<user_id>[^/]*)/admin$"),)
 
     def __init__(self, hs):
         self.hs = hs