Theiddat (Burmese: သိဒ္ဓတ်, pronounced: [θeiʔdaʔ]; 1375–1407) was the heir-presumptive of Ava from 1400 to 1406 during the reign of King Minkhaung I of Ava. Theiddat was the key figure in securing his elder brother Minkhaung I's claim on the throne of Ava. In the early days of Minkhaung's reign, Theiddat personally led an army to put down a major rebellion.