Yamaoka is a Japanese surname. Notable people with the surname include:
Akira Yamaoka (born 1968), Japanese video game composer (Silent Hill series)
Kaoru Yamaoka (1921–1986), Japanese photographer
Kristi Yamaoka (born 1987), American cheerleader
Kenji Yamaoka (born 1943), Japanese politician of the Democratic Party of Japan
Yamaoka Kagetaka (1526–1585), samurai
Yamaoka Tesshū (1836–1888), samurai
Fictional characters:
Shirō Yamaoka, protagonist of the manga series Oishinbo