This proceedings volume collected papers and posters presented at the 2013 symposium on Physics in Collision — the 33rd in the well-established series of international symposia that started in 1981, Blacksburg, Virginia — with an aim of encouraging discussions on new experimental results and their implications. The proceedings cover topics such as electroweak phenomena, searches for Higgs bosons, searches for phenomena beyond the Standard Model, Quantum Chromodynamics, heavy flavor physics, neutrino and astroparticle physics, in all aspects including the current and future experimental facilities and the theoretical ideas.