The 27th International Symposium on Lepton Photon Interactions at High Energies will take place in Ljubljana, Slovenia between August 17-22, 2015. The Conference follows the tradition of a long series of high energy physics conferences, the International Symposia on Lepton and Photon Interactions at High Energies. The program features plenary sessions covering topics of major interest to the particle physics community. A poster session will be organized where students and young postdocs may present their work. The conference is hosted by the Jozef Stefan Institute and University of Ljubljana, and will take place at the Ljubljana Exhibition and Convention Centre.