Autocross is a form of motorsport in which competitors are timed to complete a short course using automobiles on a dirt or grass surface, excepting where sealed surfaces are used in United States. Rules vary according to the governing or sanctioning body, such as the length of the course, the amount of permitted attempts, or whether competitors start the course individually at intervals or at the same time as others. In this latter form, Autocross differs from other forms of motor racing by using a system of heats or alternative timing methods for the classification rather than racing for position and declaring the first across the finish line as the winner.

Motorsport(s) or motor sport(s) are sporting events, competitions and related activities that primarily involve the use of automobiles, motorcycles, motorboats and powered aircraft. For each of these vehicle types, the more specific terms automobile sport, motorcycle sport, power boating and air sports may be used commonly, or officially by organisers and governing bodies.