He was born at Givet in Ardennes. His father being too poor to give him a regular musical education, his first lessons came from a poor blind organist of Givet; yet such was his aptitude that, when ten years old, he was appointed organist of the convent of the Récollets. In 1775 a German musician and organist, Wilhelm Hauser, was engaged for the monastery of Lavaldieu, a few miles from Givet, and Méhul became his occasional pupil.
In 1778 he was taken to Paris by a military officer, and placed himself under Edelmann, a harpsichord player. His first attempts at instrumental composition in 1781 did not succeed, and he therefore turned his attention to sacred and dramatic music. Gluck gave him advice in his studies. After various disappointments during his efforts for six years to obtain, at the Grand Opéra, a production of his Cora et Alonzo, he offered to the Opéra Comique his Euphrosine et Coradin, which, being accepted and performed in 1790, at once fixed his reputation. His opera, Stratonice, was also received with enthusiasm in 1792. After several less successful productions, his Adrien appeared, and his fame was further increased by his three best works, La jeunesse d'Henri IV, Uthal and Joseph, the finest of the series. Uthal was written for an orchestra without violins.
Méhul held a post as one of the four inspectors of the Paris Conservatoire, though this office made him feel continually the insufficiency of his early studies. Timoléon, Ariodant and Bion followed. Epicure was composed by Méhul, and Cherubini jointly; but the superiority of the latter was evident. Méhul's next opera, L'irato, ou l'emporté, failed. After writing forty-two operas, besides a number of songs for the festivals of the republic, cantatas, and orchestral pieces of various kinds, his health gave way, from an affection of the chest, and he died in Paris.