Roberto Antonio Mejía Díaz (born April 14, 1972) is a Dominican former professional baseball second baseman.

He most recently played for the El Paso Diablos of the American Association of Independent Professional Baseball in 2009.

Signed by the Los Angeles Dodgers as an amateur free agent in 1988, Mejia made his major league debut with the Colorado Rockies on July 15, 1993, during their inaugural season.

He appeared in his final major league game on April 11, 1997, with the St. Louis Cardinals.

This biographical article relating to a Dominican baseball second baseman is a stub.