Wealthy New York City playboy Arthur Bach (Dudley Moore) is perpetually drunk and completely rudderless. Dutifully supported by his sharp-tongued and quick-witted butler, Hobson (John Gielgud), Arthur reluctantly prepares to enter into an arranged marriage with heiress Susan Johnson (Jill Eikenberry). When he meets Linda Marolla (Liza Minnelli), a waitress from Queens, he falls head over heels in love, but if he backs out of his engagement with Susan, he may lose his fortune.
As America’s stock of athletic young men is depleted during World War II, a professional all-female baseball league springs up in the Midwest, funded by publicity-hungry candy maker Walter Harvey (Garry Marshall). Competitive sisters Dottie Hinson (Geena Davis) and Kit Keller (Lori Petty) spar with each other, scout Ernie Capadino (Jon Lovitz) and grumpy has-been coach Jimmy Dugan (Tom Hanks) on their way to fame. Madonna and Rosie O’Donnell co-star as two of the sisters’ teammates.
After a wish turns 12-year-old Josh Baskin (David Moscow) into a 30-year-old man (Tom Hanks), he heads to New York City and gets a low-level job at MacMillen Toy Company. A chance encounter with the owner (Robert Loggia) of the company leads to a promotion testing new toys. Soon a fellow employee, Susan Lawrence (Elizabeth Perkins), takes a romantic interest in Josh. However, the pressure of living as an adult begins to overwhelm him, and he longs to return to his simple, former life as a boy.