In December 1877 Cellier joined the D'Oyly Carte company as musical director at the Opera Comique in London. There he conducted "The Sorcerer" (1877), "H.M.S. Pinafore" (1878, for which he wrote the overture, based on themes from the opera), "Trial by Jury" (1878), George Grossmith's "Cups and Saucers" (1878–79), and three of his own one-act works: "Dora's Dream" (1877–78 revival), "The Spectre Knight" (1878), and "After All!" (1878–79). Cellier was conducting the performance of "Pinafore" during which the partners of The Comedy Opera Company attempted to repossess the set, and he was noted for his attempts to calm the audience during the fracas. His brother, François, succeeded him as musical director at the Opera Comique in 1879. Alfred Cellier was a conductor of a series of promenade concerts at the Queen's Theatre, Long Acre and, in 1878–1879 he was joint conductor, with Sullivan, of the Covent Garden Promenade Concerts.