| Masaru Hamaguchi | |
|---|---|
| Native name | 濱口優 |
| Born | January 29, 1972 Konohana, Osaka, Osaka, Japan |
| Medium | Television |
| Years active | 1990–present |
| Employer | Shochiku Geino |
| Genres | Owarai |
| Spouse | |
| Children | 1 |
| Relative(s) | Shuji Hamaguchi Yoshiyuki Hamaguchi |
| Notable works and roles | Yoiko |
| Website | www.shochikugeino.co.jp |
Masaru Hamaguchi (Japanese: 濱口 優, Hepburn: Hamaguchi Masaru, born January 29, 1972) is a Japanese comedian and actor from Konohana-ku, Osaka. He is the tsukkomi of the manzai duo, Yoiko, with his partner Shinya Arino.