Marcos Rafael Armas Ruiz (born August 5, 1969) is a Venezuelan former first baseman in Major League Baseball who played for the Oakland Athletics during the 1993 season.

He was listed at 6' 5" (1.95 m) and 190 lb.

He is the half-brother of former outfielder Tony Armas and uncle of pitcher Tony Armas Jr.

In one season with Oakland, Armas batted .194 (6-for-31), with one home run, two doubles, seven runs, and one run batted in in 15 games.

This biographical article relating to a Venezuelan baseball first baseman is a stub.