These reports present the results of the 2013 Community Summer Study of the APS Division of Particles and Fields (Snowmass 2013) on the future program of particle physics in the U.S. Chapter 3, on the Energy Frontier, discusses the program of research with high-energy colliders. This area includes experiments on the Higgs boson, the electroweak and strong interactions, and the top quark. It also encompasses direct searches for new particles and interactions at high energy.