Kōyō, Koyo or Kouyou (written: 光洋, 光陽, 紅葉, 紅陽, 晃洋, 浩陽 or 昂洋) is a masculine Japanese given name. Notable people with the name include:
*, Japanese baseball player
*, Japanese photographer
*, Japanese astronomer
*, American sumo wrestler
*, Japanese photographer
*, Japanese writer
*, Japanese footballer
{{DEFAULTSORT:Koyo
Japanese masculine given names