The Fourteenth Marcel Grossmann Meeting on Recent Developments in Theoretical and Experimental General Relativity, Gravitation, and Relativistic Field Theory (MG14) will take place at "La Sapienza" University in Rome (Italy) from July 12 to 18, 2015. Preregistration will take place Sunday, July 12, from 3:00 pm to7:00 pm and the official opening of the meeting will be on Monday morning, July 13. During the six day conference a wide variety of topics will be discussed in the morning plenary sessions beginning with mathematical topics on Monday, quantum aspects of gravity on Tuesday, precision tests of general relativity on Wednesday, relativistic astrophysics on Thursday, cosmology and astroparticle physics on Friday and the latest scientific news on going activities as well as the history of physics Saturday. There will be five plenary lectures each morning and up to twenty-five parallel sessions in the four weekday afternoons excluding Wednesday, which will be free for individual touring and the evening conference banquet. The plenary lectures will be held in the Aula Magna and the parallel sessions at the Departments of Physics (building "Marconi" and "Fermi"), Mathematics (building "Castelnuovo") and Chemistry (building "Cannizzaro"). The banquet will be held in a Central Location in Rome (details will be indicated soon).