Sweet Bird of Youth is a three-act drama by Pulitzer Prize-winning American playwright Tennessee Williams. First performed in 1959, the play chronicles the relationship between shiftless gigolo Chance Wayne and alcoholic has-been movie star Alexandra Del Lago, a.k.a. Princess Kosmonopolis. Chance has brought the Princess to his hometown of St. Cloud, Florida, in hope of reclaiming his former glory—and his former girlfriend—while using the Princess to launch a movie career of his own.
As Act I begins, Chance and the Princess are in bed together in their hotel room. The Princess—who uses this name to conceal her identity as Alexandra Del Lago, Movie Star—is sleeping off yet another drunken bender while Chance sips coffee. George Scudder, the chief of staff at the local hospital and a longtime acquaintance of Chance's, has heard of Chance's return to St. Cloud and stops by the hotel. George asks Chance why he's decided to come back after so many years away, and Chance explains that he wants to see his mother and his old girlfriend, Heavenly Finley, daughter of Boss Finley, the richest man and most powerful politician in town. George then breaks the news: Chance's mother has recently died. Reeling from this information, George deals another shock: George himself intends to marry Heavenly, and given how little Boss thinks of Chance, George recommends that Chance leave town at once.
After George exits, the Princess wakes, confused about where and who she is—a common occurrence, due to her near-constant drinking and frequent hash use. The Princess waxes on about the struggles of being a middle-aged movie star and how she doesn't want to retire. However, viewing her latest movie, she was stunned by her aging appearance, prompting her to flee Hollywood with her hired lover (Chance) in tow. Chance reveals that during one of her blackouts, she signed him to a contract with a movie studio she partly owns. Telling him that she can invalidate the contract, she attempts to lure him into bed. Chance responds by pulling out an audiotape in which she talks about smuggling hash into the country. He tells the Princess that unless she gives him money, he will go to the authorities. The Princess replies with an offer of her own: If he sleeps with her, she will give him money.
Later, the Princess applies her makeup as she and Chance prepare to cash her traveler's checks. Chance talks about his life up until this point. He dated Heavenly when they were teenagers but abandoned her for New York City, where he performed bit parts on Broadway. Around that time, he became a gigolo for lonely women. He joined the Navy during the Korean War because he liked the way he looked in the uniform. However, the experience caused a nervous breakdown, and he returned to St. Cloud—and to Heavenly. Boss, however, refused to let them marry.
As the Princess continues to get ready, Chance suggests that she should host a local talent show with the intent of giving the top prizes to Chance and Heavenly. Then, he reasons, he would have an excuse to take Heavenly to Hollywood with him. The Princess refuses, not wanting the publicity that would come with hosting such a contest. She decides not to go with him to cash the checks and sends him to do it himself. Though he vows to return, the Princess isn't sure if he will.
The second act opens at Boss Finley's estate. Boss rages over Chance's return. Boss orders his son, Tom Junior, to remove Chance from town because Chance once gave Heavenly a sexually transmitted disease. As a result, she had had to have a hysterectomy.
Chance arrives outside and speaks to Heavenly's Aunt Nonnie, who halfheartedly likes and defends him to Boss and Tom Junior. Inside, Boss and Tom Junior, who are running for reelection on the same ticket, quarrel. Tom Junior informs Boss that he knows Boss has a mistress, Miss Lucy. Moreover, to the outrage of Boss, that mistress has told Tom Junior that Boss is unable to have sex.
Heavenly enters and Boss reiterates that he wants her to act like a proper young woman. She bristles at his implication and accuses him of driving Chance away and trying to arrange a failed series of marriages with older men. Boss tells Heavenly she must go to that evening's political rally, or he will hurt Chance, who is now back in town. This is the first she has heard of Chance's return.
In the next scene, Miss Lucy is at the bar of Chance and Alexandra's hotel talking about Boss's temper and (lack of) sexual performance. Chance enters, and Nonnie and Miss Lucy warn him to leave town.
The Princess stumbles in, drunken and dazed. As Chance is about to take her upstairs, Heavenly and Boss enter, but before they can speak to one another, Boss pulls Heavenly out of the bar.
Chance confronts Tom Junior about why he is being kept from Heavenly. That is when he learns that he gave Heavenly an STD—and that if he doesn't leave town by midnight, Boss will have him castrated.
The Princess goes back to their room, and Chance watches the Finley rally on the bar television. A heckler in the crowd asks Boss about Heavenly's operation, and Heavenly collapses in embarrassment.
In Act III, the Princess is trying to find someone to take her from St. Cloud. Chance enters their room, drunk, and calls a Hollywood gossip columnist with the intention of having the Princess discuss the two new rising stars in her midst, Chance and Heavenly. However, the columnist informs the Princess that her movie—the one in which she so feared her looks—is a hit. Her career is on an upward trajectory. The Princess tries to get Chance to leave with her, but he won't. After her departure, Tom Junior and a group of men enter the room to follow through with Chance's punishment.