Emperor Gengshi of Han (d. strangled CE 25), also known as the Prince of Huaiyang (the title that Emperor Guangwu (Liu Xiu) gave him in absentia after he was deposed by Chimei forces), courtesy name Shenggong, is an emperor of the restored Chinese Han Dynasty following the fall of Wang Mang's Xin Dynasty.

He is not to be confused with Emperor Guangwu, who founded the succeeding Eastern Han Dynasty.

He is viewed as a weak and incompetent ruler, who briefly rules over an empire willing to let him rule over them, but is unable to keep this empire together.

He is eventually deposed by the Chimei and strangled a few months after his defeat.

Traditional historians treat his emperor status ambiguously—and sometimes he is referred to as an emperor (with reference to his era name—thus, Emperor Gengshi) and sometimes is referred to by his Eastern Han-granted title (Prince of Huaiyang) because Eastern Han is later viewed as the "legitimate" restoration of the Han Dynasty, implying that he was only a pretender.