A checked swing is a type of motion in baseball made by a batter, sometimes also referred to as a "check-swing" or "check swing". A checked swing is not an official term or call in baseball, such as a strike or ball, but is a common phrase used by commentators, fans, players, etc. to describe a situation in which a batter starts to swing the bat at a pitched ball, but stops the swing in order to allow the ball to pass without hitting it. The call or outcome of a so-called checked swing relies entirely on whether or not the umpire determines the motion to have been a swing or not to have been a swing. After the determination of whether or not a swing has occurred, regular rules governing the call of strikes or balls apply

In baseball, batting is the act of facing the opposing pitcher and trying to produce offense for one's team. A batter or hitter is a person whose turn it is to face the pitcher. The three main goals of batters are to become a baserunner, to drive runners home or to advance runners along the bases for others to drive home, but the techniques and strategies they use to do so vary. Hitting uses a motion that is virtually unique to baseball and its fellow bat-and-ball sports, one that is rarely used in other sports. Hitting is unique because it involves rotating in the horizontal plane of movement, unlike most sports movements which occur in the vertical plane.