Kawaguchi (written: 川口 literally means "river mouth") is a Japanese surname. Notable people with the surname include:

Ekai Kawaguchi (1866-1945), Japanese Buddhist monk

Hiroshi Kawaguchi (composer) (born 1965), Japanese composer and keyboardist

Junnosuke Kawaguchi (born 1961), Japanese bassist

Kaiji Kawaguchi (born 1948), Japanese manga author

Keiichiro Kawaguchi, Japanese animator and director

Masafumi Kawaguchi (born 1973), Japanese player of American football

Matsutarō Kawaguchi (1899-1985), Japanese writer

Kiyotake Kawaguchi (1892-1961), Japanese general during World War II

Senri Kawaguchi (born 1997), Japanese drummer

Takao Kawaguchi (born 1950), Japanese judoka

Yoichiro Kawaguchi (born 1952), Japanese computer graphics artist

Yoriko Kawaguchi (born 1941), Japanese politician

Yoshikatsu Kawaguchi (born 1975), Japanese footballer

Yuko Kavaguti (born 1981), Japanese Russian pair skater

Yutaka Kawaguchi (born 1973), Japanese ice hockey player

Japanese-language surnames

Kawaguchi (surname)