Les Huguenots (French pronunciation: [le ˈyg(ə)no]) is an opera by Giacomo Meyerbeer and is one of the most popular and spectacular examples of grand opera. In five acts, to a libretto by Eugène Scribe and Émile Deschamps, it premiered in Paris on 29 February 1836.

Les Huguenots was some five years in creation. Meyerbeer prepared carefully for this opera after the sensational success of Robert le diable, recognising the need to continue to present lavish staging, a highly dramatic storyline, impressive orchestration and virtuoso parts for the soloists – the essential elements of the new genre of Grand Opera. Meyerbeer and his librettist for Robert le Diable, Eugène Scribe, had agreed to collaborate on an epic work concerning the French Wars of Religion, with a drama partly based on Prosper Mérimée's 1829 novel A Chronicle of the Reign of Charles IX. Coming from a wealthy family, Meyerbeer could afford to take his time, dictate his own terms, and to be a perfectionist. The very detailed contract which Meyerbeer arranged with Louis-Désiré Véron, director of the Opéra, for Les Huguenots (and which was drawn up for him by the lawyer Adolphe Crémieux) is a testament to this. While Meyerbeer was writing the opera, another opera with a similar setting and theme (Le pré aux clercs by Ferdinand Hérold) was also produced in Paris (1832). Like Meyerbeer's, Hérold's work was extremely popular in its time, although it is now only seldom performed.

Meyerbeer decided that he wanted more historical details of the period and a greater psychological depth to the characters than Scribe's text was supplying so he obtained Scribe's approval to invite a second librettist, Émile Deschamps, to collaborate on the text in order to furnish these elements. Meyerbeer was recommended to take his wife to a warmer climate for her health, and while in Italy for that purpose he consulted with the librettist of his earlier Italian operas, Gaetano Rossi. With his advice Meyerbeer himself re-wrote the part of Marcel, one of the most striking and original characters in the piece. Meyerbeer also accepted the advice of star tenor Adolphe Nourrit, chosen to create the part of Raoul, to expand the love duet in Act 4, which became one of the most famous numbers in the opera.

Les Huguenots was premiered by the Paris Opera at the Salle Le Peletier on 29 February 1836 (conductor: François Habeneck), and was an immediate success. Both Adolphe Nourrit and Cornélie Falcon were particularly praised by the critics for their singing and performances. It was indeed Falcon's last important creation before her voice so tragically failed in April of the following year. Hector Berlioz called the score "a musical encyclopedia". Les Huguenots was the first opera to be performed at the Opéra more than 1,000 times (the 1,000th performance being on 16 May 1906) and continued to be produced regularly up to 1936, more than a century after its premiere.(The Paris Opera opened a new production of Les Huguenots in September 2018, the first time since 1936 for the opera to be performed there). Its many performances in all other of the world's major opera houses give it a claim to being the most successful opera of the 19th century.

Other first performances included London (Covent Garden Theatre), 20 June 1842, and New Orleans (Théâtre d'Orléans) on 29 April 1839. Due to its subject matter it was sometimes staged under different titles such as The Guelfs and the Ghibellines (in Vienna before 1848), Renato di Croenwald in Rome, or The Anglicans and the Puritans (in Munich), to avoid inflaming religious tensions among its audiences.

Les Huguenots was chosen to open the present building of the Covent Garden Theatre in 1858. During the 1890s, when it was performed at the Metropolitan Opera, it was often called 'the night of the seven stars', as the cast would include Lillian Nordica, Nellie Melba, Sofia Scalchi, Jean de Reszke, Édouard de Reszke, Victor Maurel and Pol Plançon. The opera was performed in Italian at the Met in the 19th century as Gli Ugonotti.

In the Soviet Union, the opera was given a new libretto as Dekabristy, about the historical Decembrists.

As with Meyerbeer's other operas, Les Huguenots lost favor in the early part of the twentieth century and it fell out of the operatic repertoire worldwide, except for very occasional revivals. Dame Joan Sutherland and Richard Bonynge were the major force in the opera's revival during the second half of the 20th century. Sutherland chose the opera for her final performance at the Sydney Opera House on 2 October 1990, Bonynge conducting the Opera Australia Orchestra.