A fielder is a person who plays in the outfield during a game of baseball. The outfield consists of three positions: left field, center field and right field. A fielder's responsibility is to catch or intercept balls hit by the batter and throw them back to the pitcher on the mound as quickly as possible to get the runner out. Fielder also refers to a player who takes part in any team sport where they are responsible for defending their goal, such as soccer or hockey.