Ostrów [ˈɔstruf] is a village in the administrative district of Gmina Gać, within Przeworsk County, Subcarpathian Voivodeship, in south-eastern Poland.

In 1772-1918 the town belonged administratively to the Ruthenian Voivodeship of the Habsburg crownland Kingdom of Galicia and Lodomeria.

The village is situated on a frontal moraine headland, which cuts with its high banks into the Markówka valley as flat as a table (Mleczka tributary) .

She was the only child of the Sandomierz voivode heir Sietesza Otto from Pilcza and Jadwiga Melsztyńska (daughter of Jan, godmother of Jagiełło, sister of Spytka ).

When Elzbieta's father died in 1384, she inherited the huge properties of Łańcut, Ostrów and Pilica, becoming the richest virgin in Poland.

On 12 December 1410 Elżbieta became a widow and married King Władysław II Jagiełło in Sanok on 2 May 1417, and thus Ostrów became a royal town.

In 1583, Ostrów belonged to the Jaroslawski family and paid tax from 16 ¼ of the canon's land and from two water mills .

In the summer of 1624 a Nogais Tatar horde led by Khan Temir destroyed the Ostrów church, Białoboki villages and overran Korniaktów Castle.

The Tatars were stationed in a ravine in nearby Wolica - in ramparts and arranged there a weapons warehouse called zwolicą.

During the battle of the church in Nowosielce a Tatar chief was wounded, whose ordinaries brought him to Białobok fields, where he died.

At the place of his death a mound was built - a grave that still stands today, reminding of the tragic events of 1624.

The majority of villagers were captured and taken as Jasyr for sale to the Ottoman Empire where a terrible fate awaited.

The villages of the former Białoboki key including Ostrów became property of Aleksander Dominik Lubomirski (1693-1720) who died childless.

In 1882 Białoboki was recorded as part of Łańcut county, had 1083 rozl., 81 homes, 481 residents, a parish church in Urzejowice, and a municipal clearing office.

The end of World War I (1914-1918) led to the Second Polish Republic (1918-1939) until the Nazi Invasion of Poland and occupation (1939-1945).