Family name カツオ (Katsuo 
, カツオ ) , in the world, is quite a rare surname. The cognomen カツオ is habitual in Japan, where it is quite a rare surname, Albania, where it is a rare surname, and Indonesia, where it is a very rare surname. In absolute terms, it is commonest in Japan, China, and Indonesia. More prevalently, カツオ is the forename as well as the last name.