Putumayo (Spanish pronunciation: [putuˈmaʝo]) is a department of Southern Colombia.

Originally, the southwestern area of the department belonged to the Cofán Indians, the northwestern to the Kamentxá Indians, the central and southern areas to tribes that spoke Tukano languages (such as the Siona), and the eastern to tribes that spoke Witoto languages.

After the Inca defeat in 1533, the region was invaded by the Spanish in 1542, and from 1547 was administered by Catholic missions.

The current territory of Putumayo was linked to Popayan during the Spanish Colonial Period and in the first Republican decades belonged to the "Azuay Department", which included territories in Ecuador and Perú.

Later a long process of territorial redistributions began: Amazonas Antioquia Arauca Atlántico Bolívar Boyacá Caldas Caquetá Casanare Cauca Cesar Chocó Córdoba Cundinamarca Guainía Guaviare Huila La Guajira Magdalena Meta Nariño N. Santander Putumayo Quindío Risaralda San Andrés Santander Sucre Tolima Valle del Cauca Vaupés Vichada