Wesołowo [vɛsɔˈwɔvɔ] is a village in the administrative district of Gmina Wielbark, within Szczytno County, Warmian-Masurian Voivodeship, in northern Poland.

It lies approximately 8 kilometres (5 mi) north-west of Wielbark, 17 km (11 mi) south-west of Szczytno, and 45 km (28 mi) south-east of the regional capital Olsztyn. It is located in the historic region of Masuria.