The story unfolds on a bright summer morning in the 1890s, in New York City, as residents eagerly anticipate the arrival of the charming matchmaker, Dolly Levi. A versatile widow of a dry-goods merchant, Dolly is embarking on a mission to Yonkers, tasked with arranging the second marriage of the affluent yet cantankerous Mr. Horace Vandergelder. Vandergelder, a self-proclaimed "half-a-millionaire", believes that nearly everyone around him is foolish, and he shares his intentions for remarriage, which he considers a foolhardy endeavor.
Upon her arrival, Dolly takes charge of the social scene, eliminating competition for Vandergelder’s affections, including the young widow Mrs. Irene Molloy, whom she recently introduced to him. To garner Vandergelder's interest in a prospective heiress, Dolly spins a tale about Ernestina Semple, convincing him to meet her that very afternoon during the 14th Street Association Parade.
As the plot thickens, Cornelius Hackl and Barnaby Tucker, Vandergelder’s long-suffering clerks, decide to abandon the mundane life of Yonkers for the excitement of New York City. In the bustling city, they find themselves hiding in Mrs. Molloy’s shop to escape Vandergelder. Meanwhile, Dolly, along with Mrs. Molloy and her assistant Minnie Fay, works diligently to mislead the inquisitive Vandergelder.
However, when Vandergelder suspects something is amiss, he angrily cuts ties with Mrs. Molloy and continues his plans to meet the alleged heiress. Frustrated but resourceful, Dolly plays matchmaker once more, orchestrating a delightful dinner at the famed Harmonia Gardens Restaurant for Cornelius, Barnaby, Mrs. Molloy, and Minnie Fay. Teaching them to dance, she breathes life into their escapades, imbuing the experience with joy and sociability.
As Dolly reflects on her own desires to reconnect and embrace life beyond her solitude, she elaborates to her late husband about her wish to marry Vandergelder. The vibrant scenes of celebrations and parades unfold, highlighting Dolly’s strong determination to reclaim her place in the world. The excitement culminates at the Harmonia Gardens, where the staff prepares to welcome Dolly, dazzling in her striking red dress, much to the shock of Vandergelder.
In a series of comedic misunderstandings, Vandergelder discovers Cornelius and his niece Ermengarde at the restaurant, leading to a whirlwind of events that challenge his stoic demeanor. Confronted with the reality of his life without Dolly, Vandergelder realizes that he has been a fool for denying her. In a heartfelt turn of events, Dolly, anticipating his change of heart, is ready to accept his apologies and a proposal as he jubilantly sings "Hello, Dolly!" to conclude their delightful journey together.
