In the game of baseball, the official scorer is a person appointed by the league to record the events on the field, and to send the official scoring record of the game back to the league offices. In addition to recording the events on the field such as the outcome of each plate appearance and the circumstances of any baserunner's advance around the bases, the official scorer is also charged with making judgment calls that do not affect the progress or outcome of the game. Judgment calls are primarily made about errors, unearned runs, fielder's choice, the value of hits in certain situations, and wild pitches, all of which are included in the record compiled. This record is used to compile statistics for each player and team. A box score is a summary of the official scorer's game record.

Baseball scorekeeping is the practice of recording the details of a baseball game as it unfolds. Professional baseball leagues hire official scorers to keep an official record of each game, but many fans keep score as well for their own enjoyment. Scorekeeping is usually done on a printed scorecard and, while official scorers must adhere precisely to one of the few different scorekeeping notations, most fans exercise some amount of creativity and adopt their own symbols and styles.