Kanai (written: 金井) is a Japanese surname. Notable people with the surname include:
- Hideta Kanai (金井 秀太, born 1938), Japanese javelin thrower
- Hiroyuki Kanai, Japanese philatelist
- Katsu Kanai, Japanese film director
- Kikuko Kanai (1911–1986), Japanese composer
- Kota Kanai (金井 恒太, born 1986), Japanese shogi player
- Kiyotaka Kanai, astronomer
- Lincoln Kanai, Japanese-American activist
- Mieko Kanai, fiction writer
- Mika Kanai, voice actress, also known as Mika Yamadera
- Mitsunari Kanai, aikido teacher
- Norishige Kanai, Japanese astronaut candidate
- Noritoshi Kanai (金井 紀年, 1923–2017), Japanese businessman
- Ryuta Kanai (金井 隆太, born 1989), Japanese footballer
- Taio Kanai (金井 大旺, born 1995), Japanese hurdler
- Yuta Kanai, actor
- Yutaka Kanai (1959–1990), Japanese long-distance runner
Fictional characters
edit- Izumi Kanai, a character in the film Battle Royale
- Kamon Kanai, antagonist in Yakuza 5