In 1916, he studied with Adolphe Hennebains, Léopold Lafleurance and Philippe Gaubert at the Conservatoire de Paris, where he graduated in 1918.

In 1922, he established the Quintette instrumental de Paris with flute, harp and string trio.

Several composers wrote for the ensemble, including Albert Roussel (Sérénade pour flûte, harpe, violon, alto et violoncelle opus 30), Vincent d'Indy (suite, opus 91), Joseph Jongen and Cyril Scott.

From 1952 to 1968, René Le Roy was a solo flute at the New York City Opera Orchestra, and until 1971 he was a chamber music teacher at the Conservatoire de Paris.

Among his students were Christine Alicot, Juho Alvas, Thomas Brown, Susan Morris DeJong, Geoffrey Gilbert and Bassam Saba.