Yamaguchi may refer to:
People
- Yamaguchi (surname), the 14th most popular Japanese surname
Places
- Yamaguchi Prefecture, the westernmost prefecture of Honshū island of Japan
- Yamaguchi (city), capital of Yamaguchi Prefecture
- Yamaguchi Station (Yamaguchi), a JR West railway station, located in the center of Yamaguchi-shi
- Shin-Yamaguchi Station, a Sanyō Shinkansen station in Yamaguchi-shi
- Yamaguchi (city), capital of Yamaguchi Prefecture
- Yamaguchi, Nagano, a village in Nagano Prefecture
Fiction
- Kumiko "Yankumi" Yamaguchi, the character played by Yukie Nakama in Gokusen, a Japanese TV show
- Yamaguchi-sensei, a doctor in the manga/anime series Fighting Spirit
- U.S.S. Yamaguchi, an Ambassador Class Federation starship in the Star Trek franchise
- Yamaguchi Digital Pets, a fictional digital pets company mentioned in Fanboy & Chum Chum
People
- Kristi Yamaguchi American figure skater
- Otoya Yamaguchi Japanese political assassin
Other uses
- Yamaguchi Bank, a major regional bank in Japan, primarily in the Yamaguchi prefecture
- Yamaguchi Bicycles, a custom bike frame builder in Rifle, Colorado
- Yamaguchi Broadcasting (later named KRY), a Japanese television and radio broadcasting company
- Yamaguchi Dam (China), a dam in northwest China
- Yamaguchi Dam (Nagano), a dam in Nagano Prefecture, Japan
- Yamaguchi Prefectural University
- Yamaguchi Ube Airport
- Yamaguchi University
- Yamaguchi-gumi, a yakuza group
- 15841 Yamaguchi, an asteroid named for the Japanese prefecture
- Sweden v. Yamaguchi