Hiroshi Mizushima was a Japanese actor and voice actor. He was born on September 11, 1932, in Miyagi Prefecture, Japan, and passed away on June 19, 2005. Mizushima was a founding member of the Shiki Theatre Company, a prominent theatrical troupe in Japan, alongside figures like Keita Asari and Takeshi Kusaka. His career spanned stage, film, and television, with his work in live-action productions forming the core of his professional life.

In addition to his extensive live-action work, Mizushima contributed his voice to a small number of film and television projects. His most recognized voice role is that of Prince Tulip the Giant in the 1974 animated feature film Jack and the Beanstalk. In this musical fantasy film directed by Gisaburo Sugii, he voiced the character of the slow-witted and oversized son of the story's antagonist, the witch Madam Noir.

His other notable voice performance was in the 1978 live-action science fiction film Message from Space, directed by Kinji Fukasaku. In this film, he provided the voice for the character Commander-in-Chief. He also voiced the character Brain in the 1977 tokusatsu (special effects) television series The Iron Giant 17.