Somewhere in Africa, little Jill Young buys a baby gorilla from two natives and, ignoring the warnings of her father, a farmer, names him Joe and adopts him. To lull the gorilla to sleep, Jill sings "Beautiful Dreamer," while feeding him from a baby bottle. Twelve years later, in New York, fast-talking impresario Max O'Hara prepares to leave for Africa, where he plans to collect animals and publicity for his latest venture, an exotic Hollywood nightclub. When he is approached by Gregg Johnson, a rodeo roper, about a job as an animal handler, Max gets the idea to use cowboys as part of his nightclub act and hires him. Weeks later, in Africa, Max is concocting adventure stories about himself and passing them on to his publicist, Windy, while Gregg and several other cowboys are rounding up lions for the club. As the safari is about to end, Max's camp is visited by Joe, now an enormous, full-grown gorilla. After Joe angrily frees a caged lion, he is encircled by the cowboys, who try to lasso him from their horses. Joe easily thwarts their efforts, however, and is about to throw Max over a cliff when Jill runs up and commands him to stop. Furious, Jill then informs Gregg that Joe is her friend and orders the safari off her land. Later, an apologetic Max and Gregg visit Jill, whose father has recently died, and Max convinces her to bring Joe to Hollywood to be a headliner at his Golden Safari nightclub. In Hollywood, Max advertises Joe as "Mr. Joseph Young of Africa," but refuses to reveal anything about him to the press. During the club's much ballyhooed opening, Joe dazzles the crowd when he rises up through the floor while holding a rotating platform on which Jill plays "Beautiful Dreamer" on a grand piano. Joe also plays tug-of-war with ten champion wrestlers and boxers and easily dunks all of them into a tank of water. Joe and Jill's stage success is tempered by the fact that Joe is locked in a cage every night, and Jill soon realizes that she has to return him to Africa. When she informs Max that she is quitting, however, the impresario talks her into staying until he finds a replacement act. Seven weeks later, Joe and Jill are still performing at the club, doing an act in which the audience is invited to pelt Joe, who is dressed like an organ grinder's monkey, with phony money. When one drunken customer throws a bottle at Joe's head, the great ape nearly explodes with anger. Later, while Jill and Gregg, who have fallen in love, are at their hotel, the drunken customer and his two equally intoxicated friends sneak downstairs to Joe's cage and offer him liquor to drink. Joe soon becomes drunk himself, and when one of the customers deliberately burns his hand, he breaks out of his cage in a rage. Joe chases the men upstairs, then begins to destroy the club's huge set, causing the terrified audience to run for cover. After Joe breaks the glass partition that separates the audience from a group of lions and begins fighting with the cats, Jill and Gregg arrive, as do the police. Although the police and Jill soon take control of the situation, Joe is later condemned to die. Just before Joe's execution, however, a guilt-ridden Max, who has always feared the ape, devises a scheme to save him. By faking a heart attack in front of Joe's police guard, Max gives Jill enough time to free Joe, who is then loaded into the back of a truck driven by Gregg. A furious race to the harbor, where Max has arranged for a boat to Africa, then ensues. Just before they reach the harbor, however, they see an orphanage on fire and stop to help. Gregg, Jill and Joe rescue several children from the flames, then as the building is about to collapse, Joe climbs to the roof and saves the remaining child, injuring himself in the process. Because of his heroics, Joe is freed and returns to his African home with the now-married Jill and Gregg.
