Kawaguchi (written: 川口 lit. "river mouth") is a Japanese surname. Notable people with the surname include:
Akitsugu Kawaguchi, Japanese mathematician
Debra Kawaguchi (1991-2003), 13-year-old American suicide victim featured in the Piers Anthony Novel - Air Apparent
Ekai Kawaguchi (1866-1945) Japanese Buddhist monk, and the first recorded Japanese person to travel in Nepal and Tibet
Hiroshi Kawaguchi (composer) (born 1965), Japanese composer most known for his works with Sega
Junnosuke Kawaguchi (born 1961), Japanese bassist who played for bands such as The Blue Hearts
Kaiji Kawaguchi (born 1948), Japanese manga author
Keiichiro Kawaguchi, Japanese animation director
Masafumi Kawaguchi (born 1973), American football player from Japan
Matsutarō Kawaguchi (1899-1985), Japanese author, playwright, and movie producer
Kiyotake Kawaguchi (1892-1961), Japanese general during World War II
Senri Kawaguchi (born 1997), Japanese drummer, see ja:川口千里_(ドラマー)
Takao Kawaguchi (born 1950), Olympic gold medalist in judo
Yoichiro Kawaguchi (born 1952), Japanese computer graphics artist and professor at the University of Tokyo
Yoriko Kawaguchi (born 1941), Japanese politician
Yoshikatsu Kawaguchi (born 1975), Japanese soccer player
Yuko Kawaguchi (1981), Russian (Japanese origin) pairs figure skater