| Lusai | |
| King of Lan Xang | |
| Reign: | 1432–1433 |
| Coronation: | 1432 |
| Predecessor: | Kham Tam Sa |
| Successor: | Khai Bua Ban |
| Issue: | Prince Mui Ton Kham |
| Dynasty: | Khun Lo |
| Father: | Samsenthai |
| Religion: | Therevada Buddhism |
| Birth Name: | Luvanajaya |
| Birth Place: | Muang Sua, Lan Xang |
| Death Date: | 1433 |
| Death Place: | Muang Sua, Lan Xang |
| Regnal Name: | Samdach Brhat-Anya Chao Luvana Jaya Chakrapati Phen-Pheo |
Lusai or Lue Sai was a king of Lan Xang who ruled for six months, before he committed suicide rather than face assassination by Nang Keo Phimpha. He was the oldest son of Samsenthai who had been passed over by his younger brothers. Lusai succeeded his brother Kham Tam Sa. Before he was king he was appointed as Governor of Muang Kabong. Rather than face assassination, he committed suicide in the palace gardens.