Zhu Yihai (Chinese: 朱以海; pinyin: Zhū Yǐhǎi; 1618–1662), courtesy name Juchuan (巨川), art name Hengshan (恆山) and Changshizi (常石子), was a regent of the Southern Ming dynasty from 1645 to 1653.
Zhu Yihai was born in 1618, during the 46th year of the reign of the Wanli Emperor of the Ming dynasty.
After his brother's suicide, Zhu Yihai was enfeoffed as the 11th Prince of Lu by the Chongzhen Emperor.
After four days he succeeded his peerage, Li Zicheng attacked Beijing and he fled to southern China.
His eighth son, Zhu Honghuan (朱弘桓), married the fourth daughter of Koxinga and went to live in the Kingdom of Tungning Taiwan under the protection of Zheng Jing, his brother-in-law and worked as a farmer.