Maguire solidified his stardom in 2003 with a leading role as the jockey John M. "Red" Pollard in the acclaimed film Seabiscuit, about the famous United States' racehorse Seabiscuit. In 2006, Maguire starred in his first villainous role as Corporal Patrick Tully in Steven Soderbergh's The Good German based on the Joseph Kanon novel of the same name opposite George Clooney and Cate Blanchett.

Maguire has also moved into producing. Maguire's production credits include 25th Hour (2002), Whatever We Do (2003), and Seabiscuit (2003), for which he served as executive producer.

As of November 2007, Warner Bros. has plans to fast-track a movie based on 1980's anime series, Robotech. Maguire is producing the film through his Maguire Entertainment banner and is eyeing the lead role in what the studio plans on being a tentpole sci-fi franchise. "We are very excited to bring 'Robotech' to the big screen", Maguire said. "There is a rich mythology that will be a great foundation for a