Integer programming has been widely used to solve round-robin tournament scheduling problems, either as standalone formulations or embedded in decomposition strategies. Methods applied to sports scheduling problems include branch-and-bound, branch-and-cut, Benders decomposition, and column generation. They are used to solve scheduling problems in real-life sports leagues and to tackle theoretical problems such as the traveling tournament problem or break minimization. We illustrate how integer programming can be used to model and solve a typical round-robin tournament scheduling problem. The traveling tournament problem with predefined venues is used as the motivation for studying integer programming formulations of round-robin tournament scheduling problems.