Gustavo de Jesús Gaviria Rivero (died June 15, 1991) was a Colombian drug trafficker, and a member of the Medellín cartel led by his cousin Pablo Escobar.
He began his criminal career by smuggling cigarettes and consumer electronics along with his cousin. Mateo Moreno introduced the cousins to cocaine, and they began trafficking cocaine into the United States. Initially, Gaviria handled money laundering and shipping and came up with the idea of hiding cocaine into every legitimate Colombian export. However, he left the logistics operations in the early 1980s and solely focused on money laundering, and later served as Escobar's right hand man and most importantly his voice of reasons.
He began an extramarital affair with Marina Ochoa, one of the sisters of the Ochoa brothers. The brothers came to know about the affair through Cali cartel leader Hélmer Herrera. They decided to give away Gustavo's location to the Search Bloc in exchange for not being extradited to the United States. Search Bloc commander Horacio Carrillo executed Gaviria after he refused to snitch on his cousin. His death paves way for Escobar's downfall as he is no longer there to correct Escobar when he makes mistakes.