Archeological excavations in the western part of the town show that the first settlers appeared in the Postavy region in the late Stone Age and the early Bronze Age (the late 3rd – early 2nd century B.C.).
During the early Middle Ages Postavy lands were a part of the Polotsk Principality owned by the Polotsk vice-duke. Archeologists suggest that in the place of the present-day Postavy there was a settlement called Posadnik.
In 1409 Grand Duke of Lithuania Vitovt granted Zinoviy Bratoshich a permit to rename Posadnik Postavy.
Until the mid 18th century Postavy was a small town with a marketplace and trade routes to Myadel and Druya.
The people Postavy are specially proud of are Antoniy (1733-1785) and Konstantin (1786-1853). In 1720 Postavy passed into the hands of the Tizengauz family. The reformer, enlightener and art-lover Antoniy Tizengauz tried to transform Postavy into one of the cultural-industrial centers. Architect Giuseppe de Saka designed the central part of the town: a square market, a craftsmen’s center, a court building, a school, a hotel and a doctor’s house. Craftsmen’s Barocco houses, a former hotel and Palace of Tizengauz survive in the town.
A new owner of Postavy – Konstantin Tizengauz turned the town into one of the scientific and cultural centers of Belarus. His Palace had an ornithological museum, a picture gallery and a library.
The Great Patriotic War was a glorious and tragic page in the history of the region.
During the war underground Komsomol, antifascist organizations, partisan groups named after Voroshilov, Gastello, Rokossovsky and others operated in the region and in the town.
The war dealt a sever blow to the region. The fascists killed more than 5,500 people, burned down 77 villages. The residents of the village of Altsy were burned alive. Over 2 thousand young people were taken to Germany as slave laborers. Practically every family living in the region suffered from the German invaders.
On July 5, 1944 Postavy was liberated by the soldiers of the 145th rifle division under the command of Major-General P. Dibrov.