An outfielder is a person playing in one of the three defensive positions in baseball or softball, farthest from the batter. These defenders are the left fielder, the center fielder, and the right fielder. As an outfielder, their duty is to catch fly balls and ground balls then to return them to the infield for the out or before the runner advances, if there are any runners on the bases. As an outfielder, they normally play behind the six players located in the field. By convention, each of the nine defensive positions in baseball is numbered. The outfield positions are 7, 8 and 9. These numbers are shorthand designations useful in baseball scorekeeping and are not necessarily the same as the squad numbers worn on player uniforms.

Softball is a sport similar to baseball, and it is played with a larger ball on a smaller field and with only underhand pitches permitted. Softball is played competitively at club levels, the college level, and the professional level. The game was first created in 1887 in Chicago by George Hancock.