Unlike her classmates, orphan Constance Harding is sorry to graduate from Miss Wiggins' school for girls because her only relatives, the wealthy James Clinton family, show little interest in her. They send their butler George to bring her to New York, however, and Connie finds herself in a household of self-centered Park Avenue snobs. Only the servants care about Connie, who enchants them with her sweetness and beautiful singing voice. One afternoon, Connie's cousin, Barbara Clinton, orders her to prevent socially prominent Ted Drake from going riding without her and Connie makes a fool of herself trying to keep Ted from leaving the stable grounds. When Barbara arrives, she sends Connie home, refusing to tell Ted that Connie is her cousin. Infatuated with Ted, Connie is overjoyed when she learns that the Drakes have invited the Clinton family to a ball. Because her only gown is her rather unfashionable graduation dress, the servants secretly pay for a new gown and evening slippers for her out of their own pockets. On the night of the ball, the selfish Barbara tells a lie to her mother Grace which results in Connie having to stay home. She is heartbroken, but the servants arrange to have the Clinton limousine stopped by Mike, the cook's policeman brother, and detained until midnight. Soon Connie is given a police motorcycle escort and the chief of police's car to rush to the ball, on condition that she leave by midnight. She is the sensation of the ball, captivating the audience with her singing, and Ted dances with her all evening, still unaware of her identity. After he kisses her, she suddenly realizes that it is midnight and runs away, narrowly missing Grace and Barbara, and loses one of her slippers on the staircase. While Ted is looking for its owner, Barbara realizes that Connie was at the ball. She goes home and confronts Connie, then makes up a story that Ted had merely been playing up to her for a gag. The next morning George informs Mr. Clinton that he is leaving because Barbara fired all of the servants and Connie has left. Enraged, Mr. Clinton finally lays down the law to his family and tells George that he must find Connie. Meanwhile, Connie returns to Miss Wiggins', hoping to become a music teacher. Miss Wiggins, realizing that Connie is trying to hide a broken heart, tells her to sing "One Fine Day" from Puccini's Madame Butterfly at an upcoming teacher's conference. While Connie performs the tragic love song, Ted arrives and takes her away, as Miss Wiggins smiles broadly.