Sima Yi can refer to:
- Sima Yi (father of Sima Zhao), the ancestor of the imperial family of Sima Jin
- Sima Yi (Prince of Changsha), the prince of Western Jin who participated in the War of the Eight Princes
- Sima Yi (Prince of Piling), the son of Sima Wei, Prince of Chu
- Sima Yi (emperor), the emperor of Eastern Jin