Piwonin [piˈvɔnin] is a village in Otwock County, Gmina Sobienie-Jeziory. The population is near 100. In the village is Voivodship Road 739. From 1975 to 1998 village was in Siedlce Voivodeship. It lies approximately 3 kilometres (2 mi) northwest of Sobienie-Jeziory, 19 km (12 mi) south of Otwock, and 36 km (22 mi) southeast of Warsaw.