Guillermo Patricio Kelly (b. Avellaneda, Buenos Aires, Argentina, 1921 – d. Buenos Aires, July 1, 2005) was a politician and activist, the leader of the Nationalist Liberation Alliance (ALN) of Argentina from 1953 to 1955.

Arrested after the military coup in 1955, Kelly escaped and fled the country.

He met with Israel's ambassador to Argentina, Dr. Arie Kubovy, and told him that the ALN had forsworn antisemitism.

[3] Kelly was arrested for having used a forged passport after the 1955 anti-Peronist Revolución Libertadora, a coup d'état by the military.

Aníbal Gordon, a suspected member of Triple A, a right-wing death squad founded in 1973 by the Perón government, was charged with Kelly's kidnapping and in 1985 convicted of three other murders during the early 1970s.