Jean-Léon Gérôme was born at Vesoul (Haute-Saône). He went to Paris in 1840 where he studied under Paul Delaroche, whom he accompanied to Italy (1843–1844). He visited Florence, Rome, the Vatican and Pompeii, but he was more attracted to the world of nature. Taken by a fever, he was forced to return to Paris in 1844. On his return he followed, like many other students of Delaroche, into the atelier of Charles Gleyre and studied there for a brief time. He then attended the Ecole des Beaux-Arts. In 1846 he tried to enter the prestigious Prix de Rome, but failed in the final stage because his figure drawing was inadequate.
He tried to improve his skills by painting "The Cockfight" (1846), an academic exercise depicting a nude young man and a lightly draped girl with two fighting cocks and in the background the Bay of Naples. He sent this painting to the Salon of 1847, where it gained him a third-class medal.
Gérôme abandoned his dream of winning the Prix de Rome and took advantage of his sudden success. His paintings "The Virgin, the Infant Jesus and St John" and "Anacreon, Bacchus and Cupid" took a second-class medal in 1848.
In 1851 he decorated a vase, later offered by Emperor Napoleon III of France to Prince Albert, now part of the Royal Collection at St. James's Palace, London.
In 1852 Gérôme received a commission by Alfred Emilien Comte de Nieuwerkerke, Surintendant des Beaux-Arts to the court of Napoleon III, for the painting of a large historical canvas, the "Age of Augustus". In this canvas he combines the birth of Christ with conquered nations paying homage to Augustus. Thanks to a considerable down payment, he was able to travel in 1853 to Constantinople, together with the actor Edmond Got. This would be the first of several travels to the East. This same year, Gérôme moved to the Boîte à Thé, a group of studios in the Rue Notre-Dame-des-Champs, Paris. This would become a meeting place for other artists, writers and actors. George Sand entertained in the small theatre of the studio the great artists of her time such as the composers Hector Berlioz, Johannes Brahms and Gioachino Rossini and the novelists Théophile Gautier and Ivan Turgenev.
In 1854 he made another journey to Turkey and the shores of the Danube, where he was present at a concert of Russian conscripts, making music under the threat of a lash. Also in 1854, he completed another important commission of decorating the Chapel of St. Jerome in the church of St. Séverin in Paris. His "Last communion of St. Jerome" in this chapel reflects the influence of the school of Ingres on his religious works.
In 1856 he visited Egypt for the first time. This would herald the start of many orientalist paintings depicting Arab religion, genre scenes and North African landscapes.
Gérôme's reputation was greatly enhanced at the Salon of 1857 by a collection of works of a more popular kind, such as the "Duel: after the Masked Ball".
In 1858 he helped to decorate the Paris house of Prince Napoléon Joseph Charles Paul Bonaparte in the Pompeian style. One year later, Gérôme tried to return to a more severe class of work, the painting of Classical subjects, but the picture failed to interest the public.
He married Marie Goupil, the daughter of the international art dealer Adolphe Goupil. They had four daughters and one son. Upon his marriage he moved to a house in the Rue de Bruxelles, close to the music hall Folies Bergère. He expanded it into a grand house with stables with a sculpture studio below and a painting studio on the top floor.
In 1865, Gérôme was elected, on his fifth attempt, a member of the Institut de France. Already a knight in the Légion d'honneur, he was promoted to an officer in 1867. In 1869 he was elected an honorary member of the British Royal Academy. The King of Prussia Wilhelm I awarded him the Grand Order of the Red Eagle, Third Class. His fame had become such that he was invited, along with the most eminent French artists, to the opening of the Suez Canal in 1869.
Jean-Léon Gérôme died in his atelier on 10 January 1904. He was found in front of a portrait of Rembrandt and close to his own painting "The Truth". At his own request, he was given a simple burial service without flowers. But the Requiem Mass given in his memory was attended by a former president of the Republic, most prominent politicians, and many painters and writers. He was buried in the Montmartre Cemetery in front of the statue "Sorrow" that he had cast for his son Jean who had died in 1891.
His pupils included Frederick Arthur Bridgman, Thomas Eakins, Theodore Robinson, William Picknell, Odilon Redon and J. Alden Weir, among many others.