Guillaume Balay (30 April 1871, Crozon, France - 13 December 1943, Gost-fenho-Ploujean, France) was a French composer and conductor.Balay studied composition with Paul Vidal and Vincent d’Indy.In 1899, he enlisted in the band of the 19th Infantry Regiment in Brest. In 1894, he won a first prize at the Paris Conservatory in cornet and was appointed assistant bandmaster.As a result of a competitive examination, Balay was appointed leader of the famous Garde Républicaine Band in 1911. The band was expanded to 77 musicians under his direction, and its fame increased throughout the world. Balay retired from the band on April 30, 1927. He then conducted an amateur band, the Fanfare Champenoise, for the next 10 years.