How old do you need to be to bet on horse racing in the U.S.?

In most states where parimutuel wagering is legal, players 18 and older are allowed to make wagers. Try Amwager, TVG, DRF Bets, Twinspires and other US horse betting sites. That’s also true in most European countries and the U.K., though there are exceptions. Greece, for example, doesn’t allow anyone under 23 to place a bet on the ponies.