Theodore Tugboat is a Canadian children's television series about an anthropomorphic tugboat named Theodore who lives in the Big Harbour with all of his friends. The show, which aired from 1993 to 2001, originated (and is set) in Halifax, Nova Scotia, Canada as a co-production between the CBC (Canadian Broadcasting Corporation), and the now defunct Cochran Entertainment. It was filmed on a model set using radio controlled tugboats, ships, and machinery. Production of the show ended in 2001, and its distribution rights were later sold to Classic Media (now DreamWorks Classics). The show premiered in Canada on CBC Television, then went to PBS (Public Broadcasting Service), was on Qubo in the United States, and has appeared in eighty different countries.

The show deals with life learning issues portrayed by the tugs or other ships in the harbour. Most often, the tugs have a problem, or get involved in a struggle with each other or another ship, but they always manage to help one another resolve these problems and see them through. Their main focus however, is to always make the Big Harbour the friendliest harbour in the world, and to always do a good job with their work related tasks.