Carlos Santiago Fayt (1 February 1918[1] – 22 November 2016) was an Argentine lawyer, politician, academic and a member of the Supreme Court of Justice of Argentina from 1983 to 2015.

His father, Emilio Moisés Fayt, was an Arab Christian of Syrian descent and his mother, Sara Pérez Robles, was of criollo background.

He played an active role in trade union life, heading the Buenos Aires Lawyers' Association 1963–1965, and had an extensive academic career.

Fayt was appointed to the Supreme Court by the new democratic government of President Raúl Alfonsín in 1983, despite never having served as a judge.

In the 1990s, when President Carlos Menem had increased the size of the Court and appointed several sympathetic Justices, Fayt was one of those who generally opposed the majority view.