A football pitch is the playing surface for the game of association football. Its dimensions and markings are defined by Law 1 of the Laws of the Game, "The Field of Play".

All line markings on the pitch form part of the area which they define. For example, a ball on or above the touchline is still on the field of play; a ball on the line of the goal area is in the goal area; and a foul committed over the 16.5 metres (18-yard) line has occurred in the penalty area. Therefore a ball must wholly cross the touchline to be out of play, and a ball must wholly cross the goal line (between the goal posts) before a goal is scored; if any part of the ball is still on or above the line, the ball is still in play.

The field descriptions that apply to adult matches are described below. Note that due to the original formulation of the Laws in England and the early supremacy of the four British football associations within IFAB, the standard dimensions of a football pitch were originally expressed in imperial units. The Laws now express dimensions with approximate metric equivalents (followed by traditional units in brackets), but use of the imperial units remains common in some countries, especially in the British Isles.