Big: the musical is a musical adaptation of the 1988 Tom Hanks film Big. It was directed by Mike Ockrent and featured music by David Shire and lyrics by Richard Maltby, Jr., with choreography by Susan Stroman. Big: the musical is the story of a 12-year-old boy, Josh Baskin, who grows up overnight after being granted a wish by a "Zoltar Speaks" machine at a carnival. With the aid of his best friend, Billy Kopecki, Josh must cope with his new adulthood while finding another "Zoltar" machine so that he can wish himself a kid again.

The musical opened on Broadway at the Shubert Theatre on April 28, 1996, and closed on October 13, 1996, after 193 performances. Although it was nominated for five Tony Awards, including best actress and actor, it was generally considered to be a flop.

Since the play's pre-Broadway tryout in Detroit in January 1996, a great deal of ink has been spilt about Big- most of it involving some pun on the title. Opinions were sharply divided on the Broadway production, but not on the 1997 National tour, which was a hit after much rewriting from authors, John Weidman (book), Richard Maltby, Jr. (lyrics), and David Shire (music). Alvin Klein, in his New York Times review of a 2000 production of the musical, wrote, " 'Big' cannot be cavalierly dismissed as a failed musical that was no match for a blockbuster movie. It is satisfyingly good -- and it was shortchanged."

Big continues to find a second life in amateur, local, regional, and school theater productions around the country.