Alphonse Royer, (10 September 1803 – 11 April 1875) was a French author, dramatist and theatre manager, most remembered today for having written (with his regular collaborator, Gustave Vaëz) the librettos for Gaetano Donizetti's opera La favorite and Giuseppe Verdi's Jérusalem. From 1853 to 1856, he was the director of the Odéon Theatre and from 1856 to 1862 director of the Paris Opéra, after which he was appointed France's Inspecteur Général des Beaux-Arts (Inspector General for the Fine Arts). In his later years, he wrote a six volume history of the theatre and a history of the Paris Opéra. He also translated the theatrical works of the Italian dramatist Carlo Gozzi, as well those of the Spanish writers, Miguel de Cervantes, Tirso de Molina, and Juan Ruiz de Alarcón. A Chevalier and later Officier of the Légion d'honneur, Royer died in Paris, the city of his birth, at the age of 71.

Alphonse Royer was born in Paris to a prosperous family with various commercial interests. His father was a commissaire-priseur (auctioneer) and lawyer. As a young man, Royer belonged to a literary circle inspired by Romanticism and Liberalism, movements for which he maintained a sympathy throughout his life. He initially trained to be a lawyer, but was more interested in poetry and the theatre and longed to travel. His father sent him abroad where for several years he travelled in Italy and the Middle East, and carried out several minor diplomatic and business missions. Royer was in Constantinople during the 1826 revolt of the Janissaries against Mahmud II and later wrote an account of it in his 1844 novel, Les janissaires. His experiences during those years also served as the inspirations for several other works, including his novels Venezia la bella (1834) and Robert Macaire en Orient (1840) and a collection of novellas, Un Divan (1834). On his return to Paris, Royer made his literary debut with a novel set in the Middle Ages, Les Mauvais Garçons, which he co-authored with Henri Auguste Barbier. It was published in 1830, the same year as his first venture into drama, Henry V et ses compagnons, co-authored with Auguste Romieu. The play premiered to great success at the Théâtre des Nouveautés on 27 February 1830 with incidental music by Giacomo Meyerbeer, Carl Maria von Weber, and Louis Spohr.

In the ensuing years, Royer wrote several more novels and plays, contributed articles to a variety of Parisian periodicals, and formed a close friendship and working partnership with the Belgian playwright and poet, Gustave Vaëz. Their first major collaboration was the translation and adaptation of Donizetti's opera, Lucia di Lammermoor for the French stage. The successful premiere of Lucie de Lammermoor, at the Théâtre de la Renaissance in 1839 led to several similar commissions, as well as commissions for original librettos, most notably Donizetti's La favorite (1840), and Verdi's Jérusalem (1847). During the period of the July Monarchy, Royer and Vaëz became a major force in the adaptation of Italian operas for French audiences and had a virtual monopoly of the Italian repertoire at the Académie Royale de Musique. They always worked closely with the composers and were praised for the way their writing respected the movement and rhythm of the music. In the case of translated librettos, this was made all the more difficult by having to adapt their poetry to a pre-existing score intended to be sung in another language. An anonymous critic in L'Illustration wrote of their translation for Rossini's Otello:

By virtue of work and skill, MM. Royer and Vaëz have forced our language, so cold and so unmalleable, so constrained by consonants, so loaded with epithets, to enter without too many cuts and bruises into this narrow and flexible mode of Italian poetry.

Although their collaboration on the Italian operatic repertoire ended in 1847 with Jérusalem, they later wrote the original libretto for François-Auguste Gevaert's 1853 opéra comique, Georgette ou Le moulin de Fontenoy. In addition to their work on opera librettos, Royer and Vaëz co-wrote many plays, ranging from serious drama to comédie en vaudeville, several of which premiered at the Théâtre de l'Odéon.

During this period, Royer had also achieved a minor reputation as an orientalist, partly though his novels and travel writing which were widely read at the time, but also through his biography of Mahmud II and his articles on Mahmud's legislative reforms for the legal journal, Gazette des tribunaux. He held salons at his apartment in the Rue de Navarin, attended by literary figures, artists, composers and journalists, all of whom were close friends. According to Xavier Eyma, who attended the salons at that time, they resembled a "miniature divan in Constantinople", with Turkish tobacco smoked on traditional Turkish pipes and Turkish coffee consumed in tiny cups. Amongst Royer's circle of friends at this time, in addition to Barbier and Vaëz, were Alphonse Karr, Camille Rogier (who travelled with Royer to Constantinople in 1840), Joseph Méry, Balzac, Gérard de Nerval, Théophile Gautier and Heinrich Heine. Heine, Gautier and Royer had a particularly close friendship. At several points they all lived near each other on the Rue de Navarin, at times sharing the same lodging. Royer and Gautier and their mistresses were also frequent visitors to Heine's summer house in Montmorency. In 1841, Gautier and Royer were Heine's seconds in his duel with Salomon Strauss which had involved them in lengthy negotiations with Strauss over the time, place and weapons. They were also the witnesses at Heine's marriage to his long-time mistress, Mathilde, which took place a week before the duel.

Royer had been spoken of as a possible successor to Vedel, the director of Théâtre-Français, who resigned his post in 1840. In suggesting him for the directorship, La Presse wrote:

... M. Alphonse Royer, a man of taste, tact and charming demeanor. The government would find in him an experienced and skilful supporter and an enlightened defender of our great literary traditions.