Łomna [ˈwɔmna] is a village in the administrative district of Gmina Kosów Lacki, within Sokołów County, Masovian Voivodeship, in east-central Poland. It lies approximately 6 kilometres (4 mi) south-east of Kosów Lacki, 19 km (12 mi) north of Sokołów Podlaski, and 91 km (57 mi) north-east of Warsaw.