Born in Pereira, Gaviria has been an important figure in Colombian politics. He was first elected to Congress in 1974. He served in Virgilo Barco Vargas's government, first as minister of finance and later as minister of the interior.
In 1990 he was elected President of the Republic for the Liberal Party. During his government the new constitution was adopted in 1991, and he fought against the Cartel de Cali and various Colombian guerrilla factions.
In 1994, Gaviria was elected Secretary General of the OAS, his period beginning after the end of his presidential term in August 1994). Reelected in 1999, he has worked extensively on behalf of Latin America; between November 2002 and May 2003, he served as an honest broker in finding a solution to the Venezuelan political crisis between President Hugo Chávez and the opposition.