Słupno [ˈswupnɔ] is a village in the administrative district of Gmina Radzymin, within Wołomin County, Masovian Voivodeship, in east-central Poland. It lies approximately 4 kilometres (2 mi) south-west of Radzymin, 8 km (5 mi) north-west of Wołomin, and 23 km (14 mi) north-east of Warsaw.