Eugene Onegin, Op. 24, is an opera ("lyrical scenes") in 3 acts (7 scenes), composed by Pyotr Ilyich Tchaikovsky. The libretto, organised by the composer and Konstantin Shilovsky, very closely follows certain passages in Alexander Pushkin's novel in verse, retaining much of his poetry. Shilovsky contributed M. Triquet's verses in Act 2, Scene 1, while Tchaikovsky wrote the words for Lensky's arioso in Act 1, Scene 1, and almost all of Prince Gremin's aria in Act 3, Scene 1.

Eugene Onegin is a well-known example of lyric opera, to which Tchaikovsky added music of a dramatic nature. The story concerns a selfish hero who lives to regret his blasé rejection of a young woman's love and his careless incitement of a fatal duel with his best friend.

The opera was first performed in Moscow in 1879. There are several recordings of it, and it is regularly performed. The work's title refers to the protagonist.

Tchaikovsky worried whether the public would accept his opera, which lacked traditional scene changes. He believed that its performance required maximum simplicity and sincerity. With this in mind, he entrusted the first production to the students of the Moscow Conservatory. The premiere took place on 29 March (17 March O.S.) 1879 at the Maly Theatre, Moscow, conducted by Nikolai Rubinstein, with set designs by Karl Valts (Waltz).

Two years later the first performance at the Bolshoi Theatre in Moscow took place on 23 January (11 January O.S.) 1881 with conductor Eduard Nápravník.

Outside Russia the initial reception was lukewarm, and it was slow to conquer other European cities, being seen as a Russian curiosity. The first performance outside Russia took place on 6 December 1888 in Prague, conducted by Tchaikovsky himself, although the rehearsals had been the responsibility of Adolf Čech. It was sung in Czech and translated by Marie Červinková-Riegrová.

The first performance in Hamburg, on 19 January 1892, was conducted by Gustav Mahler, in the composer's presence. Tchaikovsky was applauded after each scene and received curtain calls at the end. He attributed its success to Mahler, whom he described as "not some average sort, but simply a genius burning with a desire to conduct".

The first performance in England took place on 17 October 1892 at the Olympic Theatre in London with Henry J. Wood conducting. This performance was sung in English, to a text translated by H. S. Edwards.

Vienna first saw Eugene Onegin on 19 November 1897, conducted by Gustav Mahler.

The United States premiere was given on 24 March 1920 at the Metropolitan Opera in New York. The opera was sung in Italian.