In baseball, an inside-the-park home run is a rare play in which a batter rounds all four bases for a home run without the baseball leaving the field of play. It is also known as an "inside-the-parker", "in-the-park home run", or "in-the-park homer".

In baseball, a home run is scored when the ball is hit in such a way that the batter is able to circle the bases and reach home plate safely in one play without any errors being committed by the defensive team. A home run is usually achieved by hitting the ball over the outfield fence between the foul poles without the ball touching the field.