Yoshihiro Hamaguchi (浜口 喜博, Hamaguchi Yoshihiro?, June 23, 1926 – August 9, 2011) 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 4x200 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. He also appeared in the TV Show Shōnen Jet, a detective adventure show made by Kadokawa Pictures.