diff --git a/Lib/socket.py b/Lib/socket.py
index 21a852155abb3b3..002df2e05e1f989 100644
--- a/Lib/socket.py
+++ b/Lib/socket.py
@@ -832,7 +832,7 @@ def getfqdn(name=''):
     """
     name = name.strip()
     if not name or name in ('0.0.0.0', '::'):
-        name = gethostname()
+        return gethostname()
     try:
         hostname, aliases, ipaddrs = gethostbyaddr(name)
     except error:
diff --git a/Lib/test/test_socket.py b/Lib/test/test_socket.py
index e4b3d848923f8c9..f8c4b6f6c266df8 100644
--- a/Lib/test/test_socket.py
+++ b/Lib/test/test_socket.py
@@ -1187,6 +1187,17 @@ def test_sethostname(self):
         finally:
             socket.sethostname(oldhn)
 
+    def test_getfqdn_undefined_address(self):
+        for addr in ('', '0.0.0.0', '::'):
+            with self.subTest(addr=addr):
+                called = []
+                with mock.patch.object(
+                    socket, 'gethostbyaddr',
+                    side_effect=lambda addr: called.append(addr) or ("", [], [])
+                ):
+                    socket.getfqdn(addr)
+                self.assertFalse(called, f"gethostbyaddr was called for undefined address {addr!r}")
+
     @unittest.skipUnless(hasattr(socket, 'if_nameindex'),
                          'socket.if_nameindex() not available.')
     @support.skip_android_selinux('if_nameindex')
diff --git a/Misc/ACKS b/Misc/ACKS
index 4a3f6482294e087..c79f5e3447f66c3 100644
--- a/Misc/ACKS
+++ b/Misc/ACKS
@@ -1877,6 +1877,7 @@ Daniel Stutzbach
 Andreas Stührk
 Colin Su
 Pal Subbiah
+Ilari Suhonen
 Michael J. Sullivan
 Nathan Sullivan
 Mark Summerfield
diff --git a/Misc/NEWS.d/next/Core_and_Builtins/2026-09-06-21-40-17.gh-issue-106505.nwL_5c.rst b/Misc/NEWS.d/next/Core_and_Builtins/2026-09-06-21-40-17.gh-issue-106505.nwL_5c.rst
new file mode 100644
index 000000000000000..894263a72702d87
--- /dev/null
+++ b/Misc/NEWS.d/next/Core_and_Builtins/2026-09-06-21-40-17.gh-issue-106505.nwL_5c.rst
@@ -0,0 +1,2 @@
+Fix ``getfqdn()`` attempting to resolve the computer's own hostname, instead
+of returning it as-is.