Author(s): Roberto Franceschini, Doojin Kim, Kyoungchul Kong, Konstantin T. Matchev, Myeonghun Park, and Prasanth Shyamsundar Kinematic variables are important tools for analyzing collider experiments. This article reviews a variety of such tools, which were designed primarily for the experiments at the Large Hadron Collider, but which have potential uses in other experiments. The article also discusses the interconnection and mutual complementarity of kinematic variables and modern machine-learning techniques. [Rev. Mod. Phys. 95, 045004] Published Tue Nov 21, 2023