Lilienthal is a German surname. Notable people with the surname include:
Alfred Lilienthal, American author
Andor Lilienthal, Hungarian chess player
David E. Lilienthal, (1888-1981) American public official at TVA and Atomic Energy Commission
Gustav Lilienthal, German aviation pioneer, brother of Otto
Max Lilienthal, Early Reform Rabbi
Otto Lilienthal, German aviation pioneer, brother of Gustav
Peter Lilienthal, film director
Philip H. Lilienthal, American lawyer, camp director, and philanthropist