In baseball, an assist (denoted by A) is a defensive statistic, baseball being the rare sport in which the defensive team controls the ball. An assist is awarded to every defensive player who touches the ball (after it has been hit by the batter) prior to the recording of a putout. A fielder can receive a maximum of one assist per out recorded. An assist is also awarded if a put-out would have occurred, had not another fielder committed an error. (see also: baseball statistics)

If a pitcher records a strikeout and the catcher catches the third strike, the pitcher is not credited with an assist. However, if the batter becomes a baserunner on a dropped third strike and the pitcher is involved in gaining a putout, the pitcher is credited with an assist just as any other fielder would be.

In recent years, some sabermetricians have begun referring to assists by outfielders as baserunner kills.