Yaguchi (矢口, lit. arrow mouth) is a Japanese surname. Notable people with the surname include:

• Aki Yaguchi, a Japanese/Australian artist
• Mari Yaguchi (born 1983), a Japanese pop singer
• Masaaki Yaguchi (born 1979), guitarist for the Japanese rock band called Mucc
• Shinobu Yaguchi (born 1967), a Japanese film director and screenwriter
• Yoko Yaguchi (1921–1985), a Japanese actress, and the wife of Japanese filmmaker Akira Kurosawa for 39 years
• Yukihiko Yaguchi (born 1955), a Japanese car designer
• Yutaka Yaguchi (1932–2023), a martial artist