Hirotsu is a Japanese surname.^[1] Notable people with the surname include:

• Eiji Hirotsu (born 1967), Japanese rugby union player
• Kazuo Hirotsu (1891–1968), Japanese novelist, literary critic and translator
• Momoko Hirotsu (1918–1988), Japanese novelist
• Motoko Hirotsu (born 1953), Japanese politician
• Ryūrō Hirotsu, also Hirotsu Ryūrō (1861–1928), Japanese novelist