Act I: THE FESTIVAL
Villagers prepare a festival to celebrate the arrival of a new town bell. Swanhilda enters the village square and sees an attractive girl on the balcony of the workshop owned by the mysterious inventor, Dr. Coppelius. The girl, named Coppélia, sits motionless and does not respond to Swanhilda's call. Franz, whom Swanhilda hopes to marry, appears with flowers for Swanhilda, but is also distracted by the attractive girl on the balcony. Swanhilda secretly watches as Franz calls to the girl and begs her to come down to meet him; Coppélia rises from her chair and seemingly blows Franz a kiss. Franz is mesmerized and determined to keep her attention. Swanhilda is deeply hurt and interrupts Franz by chasing after a butterfly which, like his love for Swanhilda, Franz mistreats with disregard. Embarrassed at being caught flirting with the girl on the balcony, Franz pleads with Swanhilda to forgive him. The mayor enters with the villagers and presents the new bell; he tells the villagers that he will offer a bag of gold to any couple who marries on the day that the bell is first hung. Swanhilda wonders if Franz will remain true to her and be the husband she is fated to marry. Following a local custom, Swanhilda holds a small sheaf of wheat to her ear; if it rustles when she shakes it, then she will know that Franz loves her. The wheat does not rustle. Despite the silliness of the myth, Swanhilda and Franz are dejected by the thought of not being each other's true loves. As evening falls, Dr. Coppelius leaves his workshop and is teased by a group of boys. After chasing them off, he goes on his way, unaware that he has dropped the key. Swanhilda finds the key and prods her friends to follow her into the darkened workshop. Dr. Coppelius returns to look for his missing key, and sees that the door to his workshop is open and he enters cautiously. Meanwhile, frustrated by Swanhilda's rebuff, Franz develops his own plan to meet Coppélia by climbing a ladder to the workshop balcony.
Act II: THE DECEPTION
Swanhilda and her friends enter the workshop, which is filled with strange objects that the girls soon discover to be life-size mechanical dolls. Swanhilda finds Coppélia behind a curtain and discovers that she is also a doll. Dr. Coppelius storms into the room and chases the girls away, except for Swanhilda who hides with Coppélia behind the curtain. Dr. Coppelius begins cleaning up the mess and notices Franz coming through his workshop window; he angrily chases Franz, who declares his love for Coppélia. Realizing that Franz has confused the doll for a real girl, Dr. Coppelius schemes to take advantage of Franz's indomitable spirit by offering him wine laced with a sleeping potion. Dr. Coppelius, believing that he can incant magical powers, readies a spell to transfer the life spirit of Franz into his beloved doll, Coppélia. Unaware that Swanhilda has disguised herself as Coppélia, Dr. Coppelius is amazed when she begins to move and appears to come to life. Taunting the confused old inventor, Swanhilda has her fun with him, while covertly trying to wake the sleeping Franz. Tired by his doll's behavior, Dr. Coppelius stows her behind the curtain. Franz awakens and calls Swanhilda's friends back into the workshop; they wind up all of the mechanical dolls. The diversion allows Swanhilda and Franz to reunite and pledge their true love for one another. Dr. Coppelius is forlorn to find a lifeless Coppélia and realizes his foolishness.
Act III: THE WEDDING
With their love resolutely avowed, Swanhilda and Franz marry. The village celebrates with dances to commemorate the new bell, which will ring forevermore to announce the hours of the day, the coming of dawn, morning prayer, time of work and the wedding of true hearts.