Du Locle was a French theatre director and a librettist. From 1862 he served as assistant to his father-in-law, Émile Perrin at the Paris Opéra, moving in 1870 to the Opéra-Comique where he was co-director -with Adolphe de Leuven- in the Opéra-Comique.

He is best remembered for mounting the original production of Bizet's Carmen in 1875. His friendship with Ernest Reyer led to him providing libretti for Sigurd and Salammbô. Du Locle was responsible for completing the French original libretto of Verdi’s Don Carlos after the death of Joseph Méry. He also played a key role in the genesis of Aida in 1869-70 and is responsible for the french translation of Simon Boccanegra and La Forza del Destino. In 1876, a financial dispute arose with Verdi, and Du Locle moved to Capri. He lived in what is called today “Villa Certosella”.

According to Charles Pigot, Du Locle inspired the subject, words and music of Bizet's Djamileh. He was a pall-bearer at Bizet's funeral and made a speech at his interment at Père Lachaise.

Du Locle died in Capri.