Giełczyn [ˈɡʲɛu̯t͡ʂɨn] is a village in the administrative district of Gmina Strzegowo, within Mława County, Masovian Voivodeship, in east-central Poland. It lies approximately 5 kilometres (3 mi) west of Strzegowo, 25 km (16 mi) south-west of Mława, and 95 km (59 mi) north-west of Warsaw.