Augustów (AUDPl-Augustów.oggaU'gustuf; Augustavas, formerly known in English as Augustovo or Augustowo) is a town in north-eastern Poland. It lies on the Netta River and the Augustów Canal. It is situated in the Podlaskie Voivodeship (since 1999), having previously been located in Suwałki Voivodeship (1975–1998). It is the seat of Augustów County and of Gmina Augustów. Augustów has an area of , and as of June 2022 it has a population of 29,305.
In 1970, Augustów became officially recognized as a health and relaxation resort. In 1973, surrounding settlements were named a part of it, forming a popular resort town.
A settlement in the area was first mentioned in 1496. Augustów was established around 1540 by Bona Sforza and granted Magdeburg rights in 1557 by Sigismund II Augustus, after whom it was also named. It was laid out in a very regular manner, with a spacious market-place.
Until 1569 Augustów belonged to the Grand Duchy of Lithuania. In 1569 it became part of the Crown of the Kingdom of Poland, while its cemetery was left in the Grand Duchy, both countries formed the Polish–Lithuanian Commonwealth as a result of the Union of Lublin. Augustów was a royal city, located in the Podlaskie Voivodeship in the Lesser Poland Province of the Polish Crown. Tatar invaders destroyed Augustów in 1656, and the second half of the 17th century saw the town afflicted by plague.
In 1795 Prussia annexed Augustów in the Third Partition of Poland. In 1807, it became part of the Duchy of Warsaw, followed by incorporation into the Russian-controlled Kingdom of Poland in 1815. It was made a county seat in 1842. The local populace took part in the large Polish January Uprising of 1863–1864 against Russia. Following Russia's full annexation of the Polish kingdom in the 1860s, it was administered from Suwałki. With a population around 9400 (1875), it carried a large trade in cattle and horses, and manufactured linen and huckaback. Its canal connects the Vistula and Neman rivers and the railway reached the town in 1899, when its population was around 12,800.