The Tumaco region was settled over 4,000 years ago by the Tumaco-La Tolita peoples, whose reign stretched along the Pacific coast from northern Ecuador to southern Colombia. Hidden amongst coast's tangled mangroves are reminders of this nation, largely unstudied and unexcavated.
In 1526 Francisco Pizarro arrived on the islands. Father Onofre Estéban founded the present-day city in 1610. Several times Tuma indigenous attempted to push these invaders away, but eventually escaped into the protection the mangroves. By 1628 Tumaco had become an important port between Panama and Callao, growing haphazardly, a mélange of peoples and cultures.
The 18th century saw Tumaco being a base camp for the defense of Spain's Pacific American ports assaulted by pirates. But in 1681, 1684 and 1687, English and Dutch corsairs attacked this puerto. Such raids continued until the early 19th century. Legend says Henry Morgan hid his loot in the Isla del Morro caves.
The Comuneros de Tumaco revolted against Spanish rule in 1781. The rebellion was suppressed the following year. Slaves escaped from this uprising retreated into the swamps; those Maroons form the base of modern Tumaco's Afro-Colombian culture.
Twentieth-century Tumaco was twice destroyed by tsunamis: in 1906 and 1979; the latter left over 400 dead and 1000 missing.