Si Votha (also spelled Si Vattha) (c. 1841 - 31 December 1891) is a Cambodian prince who is briefly a contender for the throne.

He spends his entire life fighting his half brother King Norodom for the throne.

Si Votha is a grandson of King Ang Eng (1772–1796) and a son of King Ang Duong.

His biographical notes only record that he had a daughter named Neak Ang Mechas (Princess) Ang Duong Rath Votha.

Si Votha has two half-brothers, Norodom and Sisowath, with Norodom being the king's chosen heir.

Upon King Ang Duong's death, a succession struggle ensues, with Si Votha attempting to take power while his half brother, Norodom is occupied with a rebellion.

Eventually, Norodom gains the upper hand when he gains the backing of Sisowath.