Pyay (pyā), formerly Prome (prōm), city (1983 pop. 83,332), Bago region, S central Myanmar, on the Ayeyarwady River. It is a commercial town and port, with railroad connections to Yangon. One of the oldest cities in Myanmar, Pyay was founded in the 8th cent. by the Indianized Pyus, who were conquered and absorbed by the Mon kingdom of Bago, probably in the 9th cent. It was incorporated into British Burma in 1852. The ruins of the old city are near its modern namesake.