Paysandú Department (Spanish pronunciation: [pajsanˈdu]) is a department of the northwestern region of Uruguay. It has an area of 13,922 km (5,375 sq mi) and a population of 121,843. Its capital is the city of Paysandú. It borders Salto Department to its north, Tacuarembó Department to its east, Río Negro Department to its south and has the Río Uruguay flowing at its west, separating it from Argentina.
The origin of its name is debated but is likely to be of Charrúa origin.