Theodore Tugboat is a Canadian children's television series about a tugboat named Theodore who lives in the Big Harbour with all of his friends. The show originated in Halifax, Nova Scotia, Canada as a co-production between the CBC, and the now defunct Cochran Entertainment, and 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. The show premiered in Canada on CBC Television, then went to PBS, was on Qubo in the US, and at one time, had 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.