This is the Fourth Symposium on Prospects in the Physics of Discrete Symmetries, DISCRETE 2014, the latest of the DISCRETE conference series (for information on previous ones see: http://ific.uv.es/discrete08/, http://www.roma1.infn.it/discrete10/ , https://indico.cern.ch/event/202057/), which this year will take place at King's College London, Strand Campus, London WC2R 2LS, from: Tuesday, December 2 2014 till Saturday, December 6 2014. The topics covered at the DISCRETE series of conferences are: T, C, P, CP symmetries; accidental symmetries (B, L conservation); CPT symmetry, decoherence and entangled states, Lorentz symmetry breaking (phenomenology and current bounds); neutrino mass and mixing; implications for cosmology and astroparticle physics, dark matter searches; experimental prospects at LHC, new facilities. In this coming DISCRETE we shall also introduce two new topics: cosmological aspects of non-commutative space-times as well as PT symmetric Hamiltonians, (non-Hermitian but with real eigenvalues), a topic that has wide applications in particle physics and beyond. This year at King's College London we also celebrate the 150th anniversary of the publication of Maxwell’s equations, while James Clerk Maxwell was the Professor of Natural Philosophy here. Moreover it is the 60th Anniversary of the discovery of Yang-Mills Gauge theories, the 50th anniversary of the discovery of CP Violation and the 50th anniversary of the proposal of Bell's Inequalities in Quantum Physics. Hence DISCRETE 2014 can be combined with the celebration of the above anniversaries. The format of the talks will be: Plenary (40+5 min), invited research talks (30 + 5 min) and shorter presentations (25 + 5 min), selected (by the conveners of each session in consultation with the organisers) from the submitted abstracts. The conference fee for registered participants is 400 £, which covers lunches, proceedings and participation in the conference dinner that is going to take place at the historic Royal Society in Carlton House Terrace.