Underdog is a 2007 film released on August 3, 2007 featuring the super-powered cartoon character of the same name. Several other characters share names with characters from the cartoon, though it is unclear whether other similarities exist. It is produced by Spyglass Entertainment and Classic Media and distributed theatrically in the United States by Walt Disney Pictures. The titular dog was played by a real dog with computer-generated imagery (CGI) enhancements. The movie started filming in Providence, Rhode Island in March of 2006. This film is specifically based on comic book number 18 of the Underdog comics.

A laboratory accident gives an ordinary beagle named Shoeshine (voiced by Jason Lee) unparalleled superpowers, including the ability to speak with a human voice. He is soon befriended and adopted by a lonely 12-year-old boy named Jack (Alex Neuberger). The two develop an even greater bond when the boy learns of the dog’s incredible powers and they develop for the dog a secret identity as the crime-fighting pooch Underdog. Dressed in his very own superhero outfit, Underdog flies over Capitol City, protecting its citizens from unforeseen tragedies and keeping a close eye in particular on a beautiful Cavalier King Charles Spaniel named “Sweet” Polly Purebred (voiced by Amy Adams). When the dastardly, mad scientist named Simon Barsinister (Peter Dinklage) and his overgrown henchman Cad (Patrick Warburton) threaten to destroy the city, Underdog, truly “man’s best friend,” may be the citizens’ only hope.

This film is rated PG by the MPAA for rude humor, mild language, and action.

The merchandise store released on July 31, 2007 from Disney Store. Among the merchandise being release that day is a soundtrack album from Walt Disney Records, and books from Disney Publishing Worldwide.

Underdog was released on August 3, 2007, in 3,013 theaters across the US. It grossed $11,585,121 on its opening weekend, placing in third among that weekend's films in release. As of October 11, 2007, Underdog made $42,937,703 domestic box office.

Differences from the TV series:
Shoeshine/Underdog, Sweet Polly PureBread, and Riff-Raff are portrayed as real dogs in the movie. In the TV series they were anthropomorphic dogs.
In the TV series Underdog had a nerdy voice, but in the movie he has a cool teenager voice.
Simon Barsinister doesn't have green skin like he did in the TV series.
The human characters Jack and Molly were not featured in the TV series.
Cad doesn't wear a red sweater like he did in the TV series. He wears a blue lab coat.