Oleksin [ɔˈlɛkɕin] is a village in the administrative district of Gmina Kotuń, within Siedlce County, Masovian Voivodeship, in east-central Poland. It lies approximately 9 kilometres (6 mi) west of Kotuń, 23 km (14 mi) west of Siedlce, and 65 km (40 mi) east of Warsaw.