Jimmie Shannon (Chris O'Donnell) values his freedom more than life itself. As his male peers, even his best buddy, Marco (Artie Lange), begin to hook up in marriage, Jimmie continues happily plugging away with his dating lifestyle, in no rush to find "the one."
When he least expects it, Jimmie crosses paths with the adorable Anne (Renée Zellweger) and falls in love. After a three-year relationship, Jimmie feels the pressures of commitment and decides to "give in", reluctantly proposing to Anne at the most romantic of restaurants. Sensing his uncertainty and angry over his botched and lame attempt at a proposal, Anne dumps Jimmie back into the town known as "Bachelorville."
Shortly thereafter, Jimmie's grandfather (Peter Ustinov) passes away and wills a $100 million inheritance to his grandson, on the condition he marries before his thirtieth birthday, which is less than twenty-four hours away.
After seeking advice from the family attorney, Gluckman (Ed Asner) and stock broker, O'Dell (Hal Holbrook), a desperate Jimmie hastily arranges for a priest (James Cromwell) to wait in the wings while he finds a bride.
He tries to reconcile with Anne and several other ex-girlfriends, including Buckley (Brooke Shields), a well-to-do ex-debutante; Ilana (Mariah Carey), an opera singer; Monique (Katharine Towne), a chef; Daphne (Jennifer Esposito), a cop; Zoe (Stacy Edwards), a window dresser; Carolyn (Sarah Silverman), a college student; and Stacy (Rebecca Cross) a commodities broker. Through these hilarious antics, Jimmie can't help but discover the true meaning of love.