diff --git a/zerver/models.py b/zerver/models.py
index b72cb3acbf..233ad6d3ec 100644
--- a/zerver/models.py
+++ b/zerver/models.py
@@ -256,6 +256,7 @@ class Realm(models.Model):
     POLICY_FULL_MEMBERS_ONLY = 3
     POLICY_MODERATORS_ONLY = 4
     POLICY_EVERYONE = 5
+    POLICY_NOBODY = 6
 
     COMMON_POLICY_TYPES = [
         POLICY_MEMBERS_ONLY,
@@ -272,6 +273,14 @@ class Realm(models.Model):
         POLICY_EVERYONE,
     ]
 
+    INVITE_TO_REALM_POLICY_TYPES = [
+        POLICY_MEMBERS_ONLY,
+        POLICY_ADMINS_ONLY,
+        POLICY_FULL_MEMBERS_ONLY,
+        POLICY_MODERATORS_ONLY,
+        POLICY_NOBODY,
+    ]
+
     DEFAULT_COMMUNITY_TOPIC_EDITING_LIMIT_SECONDS = 259200
 
     # Who in the organization is allowed to create streams.
@@ -1743,10 +1752,13 @@ class UserProfile(AbstractBaseUser, PermissionsMixin, UserBaseSettings):
         ]:
             raise AssertionError("Invalid policy")
 
+        policy_value = getattr(self.realm, policy_name)
+        if policy_value == Realm.POLICY_NOBODY:
+            return False
+
         if self.is_realm_admin:
             return True
 
-        policy_value = getattr(self.realm, policy_name)
         if policy_value == Realm.POLICY_ADMINS_ONLY:
             return False
 
diff --git a/zerver/openapi/zulip.yaml b/zerver/openapi/zulip.yaml
index 1531c9e0e8..82a918dcec 100644
--- a/zerver/openapi/zulip.yaml
+++ b/zerver/openapi/zulip.yaml
@@ -8859,6 +8859,7 @@ paths:
                           * 2 = Administrators only
                           * 3 = Full members only
                           * 4 = Moderators only
+                          * 6 = Nobody
 
                           **Changes**: New in Zulip 4.0 (feature level 50) replacing the
                           previous `realm_invite_by_admins_only` boolean.
diff --git a/zerver/tests/test_events.py b/zerver/tests/test_events.py
index 2ca5b4777b..52e3fd90b8 100644
--- a/zerver/tests/test_events.py
+++ b/zerver/tests/test_events.py
@@ -2045,7 +2045,7 @@ class RealmPropertyActionTest(BaseAction):
             ],
             default_code_block_language=["python", "javascript"],
             message_content_delete_limit_seconds=[1000, 1100, 1200],
-            invite_to_realm_policy=[4, 3, 2, 1],
+            invite_to_realm_policy=[6, 4, 3, 2, 1],
             move_messages_between_streams_policy=[4, 3, 2, 1],
         )
 
diff --git a/zerver/tests/test_realm.py b/zerver/tests/test_realm.py
index 96a9137b21..48801e3490 100644
--- a/zerver/tests/test_realm.py
+++ b/zerver/tests/test_realm.py
@@ -778,7 +778,7 @@ class RealmAPITest(ZulipTestCase):
                 Realm.GIPHY_RATING_OPTIONS["r"]["id"],
             ],
             message_content_delete_limit_seconds=[1000, 1100, 1200],
-            invite_to_realm_policy=Realm.COMMON_POLICY_TYPES,
+            invite_to_realm_policy=Realm.INVITE_TO_REALM_POLICY_TYPES,
             move_messages_between_streams_policy=Realm.COMMON_POLICY_TYPES,
         )
 
diff --git a/zerver/tests/test_signup.py b/zerver/tests/test_signup.py
index 063a591212..eb3d9130ef 100644
--- a/zerver/tests/test_signup.py
+++ b/zerver/tests/test_signup.py
@@ -1328,6 +1328,13 @@ class InviteUserTest(InviteUserBase):
             user_profile.refresh_from_db()
             return user_profile.can_invite_others_to_realm()
 
+        realm = get_realm("zulip")
+        do_set_realm_property(
+            realm, "invite_to_realm_policy", Realm.POLICY_NOBODY, acting_user=None
+        )
+        desdemona = self.example_user("desdemona")
+        self.assertFalse(validation_func(desdemona))
+
         self.check_has_permission_policies("invite_to_realm_policy", validation_func)
 
     def test_invite_others_to_realm_setting(self) -> None:
@@ -1335,14 +1342,23 @@ class InviteUserTest(InviteUserBase):
         The invite_to_realm_policy realm setting works properly.
         """
         realm = get_realm("zulip")
+        do_set_realm_property(
+            realm, "invite_to_realm_policy", Realm.POLICY_NOBODY, acting_user=None
+        )
+        self.login("desdemona")
+        email = "alice-test@zulip.com"
+        email2 = "bob-test@zulip.com"
+        invitee = f"Alice Test <{email}>, {email2}"
+        self.assert_json_error(
+            self.invite(invitee, ["Denmark"]),
+            "Insufficient permission",
+        )
+
         do_set_realm_property(
             realm, "invite_to_realm_policy", Realm.POLICY_ADMINS_ONLY, acting_user=None
         )
 
         self.login("shiva")
-        email = "alice-test@zulip.com"
-        email2 = "bob-test@zulip.com"
-        invitee = f"Alice Test <{email}>, {email2}"
         self.assert_json_error(
             self.invite(invitee, ["Denmark"]),
             "Insufficient permission",
diff --git a/zerver/views/realm.py b/zerver/views/realm.py
index 11ad0135ec..ca35a77133 100644
--- a/zerver/views/realm.py
+++ b/zerver/views/realm.py
@@ -53,7 +53,7 @@ def update_realm(
     ),
     invite_required: Optional[bool] = REQ(json_validator=check_bool, default=None),
     invite_to_realm_policy: Optional[int] = REQ(
-        json_validator=check_int_in(Realm.COMMON_POLICY_TYPES), default=None
+        json_validator=check_int_in(Realm.INVITE_TO_REALM_POLICY_TYPES), default=None
     ),
     name_changes_disabled: Optional[bool] = REQ(json_validator=check_bool, default=None),
     email_changes_disabled: Optional[bool] = REQ(json_validator=check_bool, default=None),