Baseball at the 2003 Pan American Games was contested between teams representing Bahamas, Brazil, Cuba, Dominican Republic, Guatemala, Mexico, Nicaragua, Panama, and the United States.

The 2003 edition was the 14th Pan American Games, and was hosted by Santo Domingo.

Cuba entered the competition as the eight-time defending champions, having won each gold medal dating back to 1971.

They successfully defended their title, with the United States finishing second.

Ties within a group were broken by the team allowing the fewest runs passing to the knockout round.