Mario Sandoval Alarcón (May 18, 1923 – April 17, 2003) was a Guatemalan politician. He is the founder in 1960 of the Movimiento de Liberación Nacional (MLN). In 1954, he helped support colonel Carlos Castillo's coup against Jacobo Arbenz.
Sandoval served as Vice President from 1 July 1974 to 1 July 1978 during the presidency of Kjell Laugerud. In 1982, he placed second in that year's presidential election. He was unsuccessful again three years later, in 1985.
Sandoval deployed a series of death squads to continue the suppression that has plagued Guatemala for most of its existence. Between 1954 and 1985, more than 60,000 people were murdered (mostly indigenous), which in turn eliminated any future threat possibilities to the elite class.