Sieniawa (Polish: [ɕɛˈɲava]), is a town in southeastern Poland, in Przeworsk County in the Subcarpathian Voivodeship.

[2] Sieniawa's history dates back to the 17th century, and the town owes its existence to the once powerful Sieniawski family.

It was founded in 1676, on initiative of Voivode of Volhynia and Starosta of Lwów, Mikolaj Hieronim Sieniawski, who owned enormous estates in eastern lands of the Polish–Lithuanian Commonwealth.

In the following years, the Sieniawski family built their manor house near the fortress, and began construction of the town, together with the San river port.

In the interwar period, Sieniawa's population declined, and unemployment was high, which resulted in street fights and demonstrations.