Teosin [tɛˈɔɕin] is a village in the administrative district of Gmina Dorohusk, within Chełm County, Lublin Voivodeship, in eastern Poland, close to the border with Ukraine. It lies approximately 6 kilometres (4 mi) west of Dorohusk, 19 km (12 mi) east of Chełm, and 84 km (52 mi) east of the regional capital Lublin.