The area now known as the Treinta y Tres Department has been long populated by Indigenous peoples as evidenced by Cerritos de Indios.

It was named after the thirty three honoured patriots who fought for and secured the Independence of the old Provincia Oriental, which became Uruguay.

Cuchillas [es] ("blades") are small undulating hills that dominate the western portion of the department.

Treinta y Tres is home to the first national protected area in Uruguay, the Quebrada de los Cuervos.

As of the census of 2011, Treinta y Tres department had a population of 48,134 (23,416 male and 24,718 female) and 21,462 households[3] Demographic data for Treinta y Tres Department in 2010: 2010 Data Source:[4] A notable natural landmark is the Quebrada de los Cuervos, 44 km east of the capital city.