Ventspils (pronounced [ˈvæntspils] ( listen); Russian: Виндава; German: Windau; Livonian: Vǟnta) is a city in northwestern Latvia in the Courland historical region of Latvia, the sixth largest city in the country. As of 2012, Ventspils had a population of 41,998. Ventspils is situated on the Venta River and the Baltic Sea, and has an ice-free port. The city's name literally means "Castle on the Venta" referring to the Venta River.

Ventspils developed around the Livonian Order Ventspils Castle, built along the Venta River. It was chartered in 1314 and became an important mercantile city of the Hanseatic League.

As part of the Duchy of Courland, Ventspils blossomed as a shipbuilding center. 44 warships and 79 trading ships were built in the town, and it was from Ventspils that the Duke's fleet set out to colonize Gambia and Tobago. Metal, amber, and wood-working shops also became important to the city's development.

During the Polish-Swedish War and the Great Northern War, Ventspils was destroyed, and in 1711 a plague wiped out most of the remaining inhabitants. Ventspils fell under the control of Imperial Russia and its re-growth was stalled.