Méry was born at Marseille. An ardent romanticist, he collaborated with Auguste Barthélemy in many of his satires and wrote a great number of stories, now forgotten. Nowadays he is perhaps best remembered as the co-librettist of the original version in French of Verdi's Don Carlos, which premiered in Paris in March 1867. Also, he was the author of the play La Bataille de Toulouse which Verdi had earlier adapted for his opera La battaglia di Legnano in January 1849.

He was noted in his time for his wit and ability to improvise. He produced several pieces at the Paris theatres, and also collaborated with Gérard de Nerval in adaptations from Shakespeare and in other plays. A friend of Offenbach, he wrote libretti for three of the composer's works.

His novella Histoire de ce qui n'est pas arrivé (1854) is a significant exercise in alternate history, in which Méry imagined that Napoleon's life took a different turn in Egypt in 1799. It was translated by Brian Stableford in 2012 and is available in a collection of Méry stories entitled The Tower of Destiny.

Alexandre Dumas, père, in 1864, invited all the poets of France to display their skill by composing to sets of Bouts-Rimés selected for the purpose by Joseph Méry. Later in life Méry received a pension from Napoleon III.