Doug Gallagher (b. 1949) is an American businessman and founder of Gallagher Financial Systems, a software company based in Miami, Florida.

In 2004, he announced his candidacy in the Senate election to replace outgoing Sen. Bob Graham. A Republican, he distanced himself from Republican social issues such as the same-sex marriage debate, instead focusing on economic issues such as taxation and tort reform. After a late start in the Republican race, July polling showed him in third place behind rivals Mel Martinez and Bill McCollum, thanks in part to publicity generated by his pro-business, anti-lawyer message. Gallagher gained some attention during the race for producing a film short, "The Great Florida Picture Show," which his campaign burned onto DVDs and mailed to 400,000 Floridian voters. He was defeated by Martinez in the primary election on August 31.