These lecture notes on hyperplane arrangements are based on a lecture series at the Park City Mathematics Institute, July 12-19, 2004. They provide an introduction to hyperplane arrangements, focusing on connections with combinatorics, at the beginning graduate student level. Background material on posets and matroids is included, as well as numerous exercises. After going through these notes a student should be ready to study the deeper algebraic and topological aspects of the theory of hyperplane arrangements.