Gen'ichirō, Genichirō, Genichiro or Genichirou (written: 源一郎 or 玄一郎) is a masculine Japanese given name. Notable people with the name include:

, Japanese writer , Japanese politician , Japanese mathematician , Japanese writer , Japanese professional wrestler

Fictional characters , a main antagonist of the video game Sekiro: Shadows Die Twice , a character in the manga series The Prince of Tennis