The Pyu city states are a group of city-states that exists from c. 2nd century BCE to c. mid-11th century CE in present-day Upper Burma (Myanmar).

The city-states are founded as part of the southward migration by the Tibeto-Burman-speaking Pyu, the earliest inhabitants of Burma of whom records are extant.

The thousand-year period often referred to as the Pyu millennium links the bronze age to the beginning of the classical states period when the Pagan Dynasty emerges in the late 9th century.The city-states—five major walled cities and several smaller towns have been excavated—are all located in the three main irrigated regions of Upper Burma: the Mu valley, the Kyaukse plains and Minbu region, around the confluence of the Irrawaddy and Chindwin rivers.

Part of an overland trade route between China and India, the Pyu realm gradually expands south.

Halin, founded in the 1st century CE at the northern edge of Upper Burma, is the largest and most important city until around the 7th or 8th century when it is superseded by Sri Ksetra (near modern Pyay) at the southern edge.

Twice as large as Halin, Sri Ksetra is the largest and most influential Pyu center.

The Pyu culture is heavily influenced by trade with India, importing Buddhism as well as other cultural, architectural and political concepts, which will have an enduring influence on later Burmese culture and political organization.

The Pyu calendar, based on the Buddhist calendar, later becomes the Burmese calendar.

Latest scholarship, though yet not settled, suggests that the Pyu script, based on the Indian Brahmi script, may have been the source of the Burmese script.The millennium-old civilization comes crashing down in the 9th century when the city-states are destroyed by repeated invasions from the Kingdom of Nanzhao.

The Mranma (Burmans), who come down with the Nanzhao, set up a garrison town at Pagan (Bagan) at the confluence of Irrawaddy and Chindwin.

Pyu settlements remain in Upper Burma for the next three centuries but the Pyu gradually are absorbed into the expanding Pagan Empire.

The Pyu language still exists until the late 12th century.

By the 13th century, the Pyu have assumed the Burman ethnicity.

The histories/legends of the Pyu are also incorporated to those of the Burmans.