Sergio Alberto Montiel was an Argentine politician, lawyer, and professor of constitutional law at the National University of the Littoral. Montiel served as Governor of Entre Ríos Province for two nonconsecutive terms: He was first elected on October 30, 1983, and served his first term until 1987. Montiel served a second gubernatorial term from 1999 to 2003. Montiel supported nationalization and opposed the 1993 Pact of Olivos.