The Paris Conservatoire played a pivotal role in shaping Olivier Messiaen’s music and career. His compositional technique resulted from his student years there, and he later found creative stimulation and financial stability in the same institution as the teacher of hundreds of future composers and musicians. Indeed, Messiaen spent most of his adult life at the Conservatoire. This chapter examines Messiaen’s relationship with the Paris Conservatoire and focusses on the way it shaped French musical culture, the institution, his students, and Messiaen's musical style.