Yoshihiro Hamaguchi (浜口 喜博, Hamaguchi Yoshihiro, June 23, 1926 – August 9, 2011[1]) was a Japanese freestyle swimmer.

He represented Japan at the 1952 Summer Olympics in Helsinki, Finland.

There, he won a silver medal as a member of the 4 × 200 m freestyle relay team, alongside Toru Goto, Hiroshi Suzuki and Teijiro Tanikawa.

Also competed in the 100m freestyle advancing to the semifinals, missing the finals by a narrow margin.

After retiring he debuted as an actor in the 1955 film Buruuba as a Japanese version of Tarzan.