Harumochi OUCHI (born in 1524, date of birth unknown - June 19, 1543) was the adopted heir of Yoshitaka OUCHI who was Sengoku daimyo (Japanese territorial lord in the Sengoku period (period of warring states)) who lived in Yamaguchi, Suo Province (Yamaguchi Prefecture).
大内晴持（おおうちはるもち、大永4年（1524年）-天文(元号)12年5月7日(旧暦)（1543年6月9日））は周防国山口(山口県)の戦国大名である大内義隆の養嗣子。