In the kitchen of the Count’s manor house on Midsummer’s Eve, Christine, the cook is frying something. She is interrupted by Jean, the valet. Jean tells Christine that Miss Julie, their mistress, is behaving wildly. The Count, who is Miss Julie’s father, is away visiting family, but Julie, rather oddly, has chosen to stay behind to celebrate Midsummer with her servants, and is currently asking many of them to dance with her. Christine explains that Miss Julie has been acting oddly since her engagement ended. Jean explains that the engagement was broken when Julie attempted to “train” her fiancée with a whip like a dog. Christine and Jean are interrupted by Miss Julie, who has come to ask Jean to dance with her. Miss Julie is noticeably flirtatious and forward with Jean, who warns her that they already danced together once in the evening, and a reprise would likely cause the servants to gossip. Jean relents however, and follows Julie to dance.
After Julie and Jean leave, Christine cooks and cleans the kitchen. Jean re-enters and attempts to convince Christine to dance with him, but is quickly followed by Julie who continues to be blatantly flirtatious and is upset to find Jean being so familiar with Christine. Christine falls asleep next to the stove and Julie orders Jean to change out of his servant’s livery and come have a drink with her. Despite Jean’s protestations, Julie orders Jean to kiss her foot and “drink to her health.” Julie praises Jean as an “aristocrat” because he drinks fine wine and knows how to speak French. As they drink, Julie explains that she has had a dream in which she climbs to the top of a slick column and then has no idea how to get down, and indicates that being close to Jean is allowing her to “climb down.” In contrast, Jean explains that in his dream he is trying to climb a tall tree, but needs to get hold of the first branch which remains stubbornly out of reach. Julie asks Jean if he has ever been in love. He explains that when he was a child, he fell madly in love with Miss Julie. One day as he worked in the garden, Jean caught sight of a Turkish pavilion (an outhouse) covered in fragrant flowers. Drawn by its beauty, Jean entered to get a closer look, but soon heard someone coming. Trapped, Jean was forced to flee through the excrement in the bottom of the outhouse and out into the rose garden. There he saw Julie and was instantly bewitched by her beauty. The next Sunday, Jean put on his best clothes, determined to see Julie one more time and then go home and commit suicide by falling asleep surrounded by poisonous elderflowers.
Julie is moved by Jean’s story and asks him to take her out on the lake in a row boat. Jean councils Julie to go to sleep, because he cannot be responsible for his behavior or its effect on Miss Julie’s reputation. Soon, Miss Julie and Jean hear an oncoming crowd of servants and, fearing that they will be discovered together, flee into Jean’s bedroom. Jean promises to protect Julie against “the mob” as they exit together. The servants sing a song and dance around the kitchen before they also exit. Julie and Jean reenter the kitchen. The implication is that they have just had sex. Jean says that the servants will know what happened between them, and explains that the only option is to travel abroad. Jean will be able to start a hotel (a lifelong dream of his) and Julie can be the mistress of his house. Suddenly, Julie becomes emotional, begging Jean to tell her that he loves her. As Julie becomes more emotional, Jean becomes more harsh and businesslike. Julie explains that they need money to open a hotel and that she has no money of her own. Jean tells her that, in that case, the plan is off and they must remain on the Count’s estate. Julie is beside herself, since staying would mean she would live with a soiled reputation as Jean’s “concubine.” Jean is unsympathetic, and indeed intensifies his abuses by calling Julie a “whore” and telling her that his story about the Turkish pavilion was a lie engineered to appeal to her womanly sensitivity. Julie is horrified, but decides that she is deserving of Jean’s abuse since she was drawn to him in the first place.
Jean asks Julie to escape with him again. In response, Julie tells Jean about her upbringing. She tells him that her mother was a fiercely independent woman who raised Julie to believe in female equality and free love. Her mother’s liberal ideas made their family a laughing stock and led to bankruptcy. When Julie’s father finally took control of the estate, her mother fell ill, and their farm mysteriously burned down. Julie’s mother counseled her father to borrow the money to rebuild from a bricklayer who turned out to be her mother’s lover and absconded with their money. Julie explains that she grew up with disdain and hatred for men just like her mother. Jean is disgusted by Julie’s story, and tells her that she and her ancestors are sick. Julie cries that she wishes to die, begging Jean to tell her what to do. Jean tells her to go to her room and get ready to leave.
Christine enters and chastises Jean for the way the kitchen looks, reminding him that he agreed to go to church with her. Jean confesses that he and Miss Julie slept together and Christine is angry at him, both for his infidelity and for taking advantage of Julie. She decides she can no longer stay in the house. Suddenly, there is a bell upstairs that signals that the Count has returned from his trip. Christine exits as the sun rises, ending Midsummer’s Eve. Julie returns, ready to travel with her yellow canary. She begs Jean to flee with her and he agrees as long as they leave the canary behind, offering to kill it. Julie sobs that the canary is her only companion after her dog ran off with the gatekeeper’s pug, but she allows Jean to decapitate the canary on the chopping block. Seeing the dead bird, Julie screams for Jean to kill her as well. She screams that she wants to see all men swimming in blood and to “drink” from Jean’s open skull. She explains that she will stay and confess everything to her father who will die of shame, thus ending her bloodline.
Christine reenters and Julie begs Christine to protect her from Jean. Christine coldly refuses but Julie continues, telling Christine that the three of them could run away together to start Jean’s hotel. Christine chastises Julie for believing a fiction. She leaves, promising to tell the stable boy to stop them if they try to flee. Trapped and scared, Julie asks Jean what he would do in her position. He explains that as a noblewoman whose reputation is tainted, there is only one thing to do. Julie picks up Jean’s newly-sharpened razor and slashes the air twice, begging Jean to help her save her father from disgrace.
Having heard the Count ring the bell, Jean is frozen. In the presence of his master, Jean has no authority, and feels himself slipping back into his “menial” role. Jean screams at Julie to leave, that her presence is taking away all of his strength and resolve. Julie begs him to pretend to be the Count and give her instructions. Jean whispers into Julie’s ear. Julie asks him if she will receive grace for her action. Jean says he cannot tell her, nor does he have the strength to order her one more time. The bell rings twice and Jean tells Julie, firmly, to leave him. Julie walks resolutely out of the door, and (the audience is left to assume) takes her own life.