Westrza [ˈvɛstʂa] is a village in the administrative district of Gmina Sieroszewice, within Ostrów Wielkopolski County, Greater Poland Voivodeship, in west-central Poland. It lies approximately 2 kilometres (1 mi) south of Sieroszewice, 19 km (12 mi) east of Ostrów Wielkopolski, and 113 km (70 mi) south-east of the regional capital Poznań.