Mario Carreras (born 14 April 1966 in Buenos Aires) is a former Argentine rugby union player.
Carreras played for Olivos Rugby Club in the Nacional de Clubes.
He had his first game at the 62–4 win over Paraguay at 30 September 1987 in Santiago, Chile for the South American Rugby Championship, aged 21 years old.
He was called for the 1991 Rugby World Cup, playing in three games, one as a substitute, but without scoring.
He had his last game at the 12–27 loss to France at 4 July 1992, in Buenos Aires, in a friendly, aged only 26 years old.