Plot:
Preston Blake, hoping to be a disc jockey as a young man, slowly worked his way up and founded Blake Media, a major corporation running hundreds of television and radio stations with 50,000 employees. After 82-year-old Blake freezes to death on the summit of Mount Everest with a triumphant smile on his face, a search for his heir begins.
It is found that Blake has a living nephew named Longfellow Deeds (Adam Sandler), who runs a pizzeria in New Hampshire and also writes greeting cards in the hopes that Hallmark may be interested in one. Deeds is contacted and brought to New York City by businessman Chuck Cedar (Peter Gallagher), who is temporarily in control of Blake Media. Plans are made for Deeds to sell his shares in the company to Cedar and return home $40 billion richer, but he must remain in New York for a few days while all the legal details are worked out.
The story is major news, and reporter Babe Bennett (Winona Ryder), who works for a tabloid show called Inside Access, has a co-worker pretend to steal her purse in sight of Deeds, because their research indicated that Deeds wanted to meet a girl by "rescuing" her, the same way his father had met his mother. Deeds does so, and beats up her "robber", and Babe goes out with him under the disguise of Pam Dawson, a school nurse from a made-up town called Winchestertonfieldville, Iowa (which later turns out to be a real town, which Babe is flabbergasted to find out).
Though Babe initially hopes to just get a good story on the new heir, she eventually falls for the unfailingly kind-hearted Deeds, and decides to tell him that she is not who she says she is, but Inside Access, in concert with Cedar (who was fed the truth by the fake robber and was smitten with Babe) reveals it to Deeds first. Heartbroken and upset, Deeds decides to return home to Mandrake Falls and makes plans to donate his $40 billion inheritance to the United Negro College Fund. After returning to Mandrake Falls, he learns from Crazy Eyes (Steve Buscemi) that Cedar intends to sell off the company, which will cause thousands of people to lose their jobs (Cedar had convinced Longfellow to sell his shares by lying that he will work commanding the company in honor of Preston's lifetime of work). Babe follows Deeds to Mandrake Falls to win him back, but after saving her life when she falls through the ice over a lake, he rejects her, saying he does not really know who she is.
At a shareholders meeting, Cedar has everyone convinced to sell the company, until Deeds (who has bought a single share) arrives and manages to convince everyone not to sell. But Cedar claims control of a majority of the shares and the sale is approved. Bennett arrives and reveals that Blake's butler, Emilio (John Turturro), is Preston Blake's illegitimate son and the true heir as a result of a younger Preston having an amourous affair with his maid in 1958 (at one point he had told Deeds that Blake treated him "like a son"). Realizing Emilio is Longfellow's cousin, Deeds convinces him they must stop Cedar and that he is the rightful CEO. As a result of Emilio supplanting Longfellow as the heir, Deeds' sale of shares are retracted.
Emilio immediately takes control of Blake Media and fires Cedar. Babe then reconciles with and kisses Deeds after professing her love for him. As they leave the meeting, Emilio thanks Deeds for his support and offers him a billion dollars, some of which Deeds spends on red Corvettes for everyone in Mandrake Falls. When he returns to the pizzeria with Babe, he learns that Hallmark is interested in buying one of his greeting cards: the one he wrote for Babe when he professed his love for her. They both share a kiss as the movie ends with Crazy Eyes crashing his Corvette and is unharmed.