Forbes Field was a baseball park in the Oakland neighborhood of Pittsburgh, Pennsylvania, from 1909 to 1971. It was the third home of the Pittsburgh Pirates Major League Baseball (MLB) team, and the first home of the Pittsburgh Steelers, the city's National Football League (NFL) franchise. The stadium also served as the home football field for the University of Pittsburgh "Pitt" Panthers from 1909 to 1924. The stadium was named after British general John Forbes, who fought in the French and Indian War, and named the city in 1758.

The US$1 million ($25.9 million today) project was initiated by Pittsburgh Pirates' owner Barney Dreyfuss, with the goal of replacing his franchise's then-current home, Exposition Park. The stadium was made of concrete and steel (one of the first of its kind) in order to increase its lifespan. The Pirates opened Forbes Field on June 30, 1909 against Chicago Cubs, and would play the final game also against the Cubs on June 28, 1970. The field itself featured a large playing surface, with the batting cage placed in the deepest part of center field during games. Seating was altered multiple times throughout the stadium's life; at times fans were permitted to sit on the grass in the outfield during overflow crowds. The Pirates won three World Series while at Forbes Field and the other original tenant, the Pittsburgh Panthers football team had five undefeated seasons before moving in 1924.