Saw Zein (Burmese: စောဇိတ်, pronounced: [sɔ́ zeiʔ]; 1303–1330) was the fourth king of the Hanthawaddy Pegu from 1323 to 1330. A nephew of the kingdom's founder King Wareru, Saw Zein succeeded his brother King Saw O in September 1323. He lost the southern territories of Tenasserim coast back to his nominal overlord Sukhothai, and looked to expand his territory northwards. He died in battle in his siege of Prome (Pyay).