An individual time trial (ITT) is a road bicycle race in which cyclists race alone against the clock (in French: contre la montre – literally "against the watch", in Italian: tappa a cronometro "stopwatch stage"). There are also track-based time trials where riders compete in velodromes, and team time trials (TTT). ITTs are also referred to as "the race of truth", as winning depends only on each rider's strength and endurance, and not on help provided by teammates and others riding ahead and creating a slipstream. Individual time trial are usually held on flat or rolling terrain, although sometimes they are held up a mountain road (in Italian: cronoscalata "chrono climbing"). Sometimes the opening stage of a stage race is a very short individual time trial called a prologue (8 km or less for men, 4 km or less for women and juniors).

Starting times are at equal intervals, usually one or two minutes apart. The starting sequence is usually based on the finishing times in preceding races (or preceding stages in the case of a multi-stage race) with the highest ranked cyclist starting last. Starting later gives the racer the advantage of knowing what time they need to beat (and also makes the event more interesting to spectators). Competitors are not permitted to draft (ride in the slipstream) behind each other. Any help between riders is forbidden. The rider with the fastest time is declared the winner.