Middle-aged New Yorker Mae Swasey is dedicated to her "Contacts and Contracts" business, through which she arranges marriages for lonely, shy and sometimes unattractive people. One afternoon, Mae consults with new client Hazel Gingras; Swedish bumbler Hjalmer Johannson; and optician George Wixted, to whom she wants to introduce Hazel. Mae then discovers that wealthy client Ina Kuschner has become engaged to handsome x-ray technician Matt Hornbeck, although Matt is unaware that Mae arranged their romance. When Mae leaves Matt's office, she accidentally is given the purse of model Christina "Kitty" Bennett, and cannot resist reading a letter to Kitty from her married boyfriend, who promises to treat her better. When Kitty reclaims her purse, Mae gently advises her to end the relationship, and Kitty storms off. Later, Ina's snobbish mother refuses to pay Mae's commission, but is quick to blame Mae when Matt jilts Ina at the altar. Mae finds Matt soon after, and he explains that he could not bear to tie himself down, even though Ina's father had promised to fund his x-ray clinic. Mae reveals that she is a marriage broker and had set him up with Ina, but her humor and pragmatism overcome his brief fit of anger. On Sunday, the day when Mae fixes up couples at her home, she successfully introduces Wixted and Hazel, and Johannson and another client, Delia Seaton. Kitty also visits Mae to apologize for her rude behavior, and informs Mae that her boyfriend has proposed. Mae subtly questions Kitty about her boyfriend's wife, and makes her understand that she cannot find happiness by breaking the heart of another woman. Mae's sympathy encourages Kitty to end the relationship, and she stays the night at Mae's apartment. The next morning, remembering a story told to her by a client, Mae pretends that she has lost an earring and that Kitty has swallowed it, in order to take her to meet Matt. Matt x-rays Kitty and does not find the earring, but is attracted to her when Mae insists that she is not trying to set them up. Mae and Kitty become good friends, although Kitty is still unaware of what Mae does for a living. Mae's secretary Alice is confused when Mae turns away a prospective client, also named Mrs. Swasey, for business has not been good and Mae is behind in her bills. Mae refuses to explain her reaction and instead helps two children who want to find happiness for their widowed father. That evening, Kitty goes out with Matt, and the couple quickly fall in love. Mae plots to make Matt jealous by sending flowers to Kitty, and her scheme works as the two spend more time together. Mae assures Matt that she has had nothing to do with his romance with Kitty, and taunts him about his declarations that he would never get married. Soon after, Hazel, who is engaged to Wixted, is selecting her trousseau at Kitty's shop, when her sister-in-law unwittingly informs Kitty about Mae's profession. Infuriated that Mae has meddled in her life, Kitty confronts her and calls her business despicable. Mae is heartbroken by Kitty's rejection, as is Matt, whom Kitty refuses to see. Feeling like a failure, Mae decides to take a vacation, but her departure is interrupted by the re-appearance of the other Mrs. Swasey, Emmy. Mae is cold toward Emmy, for twenty years earlier, Emmy had stolen Mae's husband Frank. Emmy confides in Mae that since Frank's death, she has been terribly lonely, and because she is no longer young and cute, she needs help finding another man. Mae is comforted by Emmy's confession but refuses to help her, then leaves for a health resort called Sharon Springs. As the weeks pass, Kitty begins to regret her harsh words to Mae and goes to find her at her her office. There, Mae's longtime friend, newspaper advertising executive Doberman, informs Kitty how badly she hurt Mae, who performs a much-needed service by helping socially inept people find happiness. Hoping to atone, Kitty arranges for fishing fleet owner Dan Chancellor to meet Mae at Sharon Springs, and a romance between the two blossoms. Kitty also reconciles with Matt, who proposes, and they share their good news with Mae upon her return. Matt inadvertently reveals that Kitty arranged Mae's romance, however, and Mae realizes that the staid Dan is not right for her. Mae fixes Emmy up with Dan, however, and happily returns to her office, where Doberman reveals that he is romantically interested in her himself.