Participation in sport tourism is characterized by constraints. It is constrained by spatial barriers such as travel distance and physical barriers such as fitness, along with a broad range of other factors that have yet to be systematically considered. Leisure constraint theory provides a strong foundation from which to gain insight into this dimension of sport tourism. The merits of using this approach are articulated in this essay by first highlighting the existence of constraints in sport-related travel. Next, key developments in leisure constraint theory such as the introduction of the ideas of negotiation and a hierarchical order of constraint factors are presented. The most recent developments in modelling constraints are then described and considered in the realm of sport tourism in general. Finally, to illustrate the merit of leisure constraints models in a specific sport tourism context, downhill skiing is used as an exemplar.