Sielc [ɕɛlt͡s] is a village in the administrative district of Gmina Ostrów Mazowiecka, within Ostrów Mazowiecka County, Masovian Voivodeship, in east-central Poland. It lies approximately 7 kilometres (4 mi) west of Ostrów Mazowiecka and 86 km (53 mi) north-east of Warsaw.