A Garden. In the garden of the Larina country estate, Madame Larina and nurse Filipevna can hear Mme. Larina's two daughters, Tatyana and Olga, sing a song about love. Mme. Larina begins to reminisce about her own marriage to a man she did not love; “The good Lord sends us habit as a substitute for happiness,” she concludes. The workers on the estate sing and dance to celebrate the harvest. Tatyana is lost in the romantic literature she loves, while her younger, more carefree sister Olga wants to join the celebration. Mme. Larina warns Tatyana that real life is different from her stories. Filipevna announces that two young men have arrived. Olga's fiancé Lensky, a poet, and his new friend Eugene Onegin enter. Tatyana is immediately attracted to Onegin, who tells her he has inherited a nearby estate and how dull he finds the country. Filipevna recognizes the effect Onegin has had on Tatyana.
Tatyana's Room. Tatyana is dressed for bed, but she is restless and unable to sleep. She asks Filipevna to tell her stories about her youth and marriage. Tatyana confesses that she has fallen for Onegin. Once alone, she pours her heart out into a letter to Onegin. Filipevna enters to wake Tatyana, and Tatyana convinces her to have her grandson deliver the letter to Onegin.
Another part of the estate. Servant girls on the estate sing songs while they pick fruit. Meanwhile, Tatyana anxiously awaits Onegin's response to her letter. Onegin enters and explains that he is not a man who falls in love easily. He expresses that he is unworthy of her love and can only offer her friendship. He warns Tatyana to stay in control of her emotions. The servant girls are heard singing again. Devastated, Tatyana is unable to reply.
The ballroom of the Larin estate. Against his better judgment, Onegin accompanies Lensky to a party celebrating Tatyana’s name day. Onegin dances with Tatyana but becomes increasingly irritated by the gossipy old neighbors, whom he overhears discussing him and Tatyana maliciously. An elderly French fop, M. Triquet, sings a song he has composed honoring Tatyana. Onegin decides to punish Lensky for dragging him to this miserable party by flirting with Olga. Enraged, Lensky challenges Onegin to a duel. Onegin reluctantly accepts the challenge.
A barren field. Lensky and his second, Zaretsky, wait for Onegin. Lensky reflects on his life, his poetry, his fear of death, and his love for Olga. Onegin arrives with his servant, Guillot. Both Onegin and Lensky are reluctant to go forward with the duel, but neither has the courage to stop it. Zaretsky gives the signal. Onegin shoots and kills Lensky.
A nobleman's house in St. Petersburg. Five years later, Onegin, who fled Russia after the duel, returns to the imperial capital and attends a ball. He reflects on the emptiness of his life and his remorse for killing Lensky. Prince Gremin, Onegin’s wealthy older relative, enters and introduces his wife. Onegin is astonished to see that the Prince has married Tatyana. Tatyana is also surprised to see Onegin, but tries to suppress her emotion. Dazzled by Tatyana's beauty and nobility, Onegin realizes that he is now in love with her. He decides to write to her to arrange a meeting.
Prince Gremin's home. Onegin's letter has disturbed Tatyana by stirring up the emotions she once felt for him. Onegin arrives; Tatyana asks why he is pursuing her now. Is it because she is no longer a simple girl from an obscure backwater, but a lady of high and fashionable society? Onegin tells her his love is genuine and begs her to run away with him. Brought to tears by his plea, Tatyana admits that she still loves him, but explains that their union will never be. Onegin implores her, but Tatyana is determined to remain faithful to her husband. Tatyana bids him farewell forever. Alone, ashamed, and despairing, Onegin rails against his fate.