In baseball, being hit by a pitch refers to the batter being hit in some part of the body by a pitch from the pitcher. In baseball statistics, hit by pitch (denoted by HBP) records the number of times a batter is awarded first base by virtue of being hit by a pitched ball. In pitching statistics it also records the number of times a batter opposing the pitcher is awarded first base due to being hit by a pitch. Less commonly, the terms hit batter or hit batsman are used.

A batter becomes a baserunner and is awarded first base when he or his equipment (except for his bat) is touched by a pitched ball outside of the strike zone, and he attempts to avoid it or had no opportunity to avoid it.

It is often incorrectly thought that a hit by pitch is not awarded on a pitch that has touched the ground. Such a bouncing pitch is like any other, and if a batter is hit by such a pitch, he will be awarded first unless he made no attempt to avoid it.

Pitching "inside" or near a batter in an attempt to deceive him with the pitch or to make him "back off"--move move farther from the plate--is a legitimate, common, and legal tactic. "Headhunting" or "beaning", the act of deliberately throwing the baseball at the batter in an attempt to injure or intimidate him, is strictly forbidden by the rules of baseball. It is often difficult, however, for the umpire to enforce this rule, as it requires judgment on whether a pitch close to a batter was intended to intimidate or injure him or was merely "one that got away"; that is, was thrown poorly.

In Major League Baseball, if a player commits an unsportsmanlike act such as taunting or unnecessary roughness on the basepaths, opposing pitchers will often retaliate by illegally pitching a beanball at him later in the game; in this matter, the participants themselves may police the game to a certain degree. There is a expectation for pitchers to "come to the aid" of their offended teammates by retaliating on their behalf. Headhunting is somewhat more common in the American League than in the National League, because pitchers are required to bat in the National League and are therefore subject to illegal retaliation. This type of retaliation and "bad blood" conduct is far less common in lower levels of baseball.

In the 2004 season, in an attempt to cut down on headhunting in the American League, umpires began freely ejecting pitchers who throw directly at a batter's body. Baltimore Orioles pitcher Jorge Julio was suspended in September under this change in policy after throwing a pitch at Minnesota Twins infielder Augie Ojeda 's head on September 7.