The men's 50 metre breaststroke at the 2007 World Aquatics Championships took place on 27 March (heats and semifinals) and on the evening of 28 March (final) at Rod Laver Arena in Melbourne, Australia. 136 swimmers were entered in the event, of which 127 swam. Existing records at the start of the event were: * World record (WR): 27.18, Oleg Lisogor (Ukraine), 2 August 2002 in Berlin, Germany. * Championship record (CR): 27.46, James Gibson (Great Britain), Barcelona 2003 (22 July 2003)