The Big Harbour is the harbour in which Theodore and his friends live. It is a major port with an oil refinery, container terminal, Oceanic Institute, Coast Guard, Repair Dock, Junk Dock, Ferry Terminal, and the Naval Dock. Located in Nova Scotia, Canada, the Big Harbour is the friendliest harbour in the world.
- The Dispatcher
- The Clock Tower
- Donald Dock
- Phillip and Filmore
- Benjamin Bridge
- Owan (occasionally)
- In French, the Big Harbour is named "Le Grand Port".
- The original set used to film the show is on display at the Maritime Museum of the Atlantic.
The Great Ocean Tug and Salvage Company Dock is the dock where Theodore, Hank, George, Foduck, and Emily live. The Dispatcher is attached to the dock and from there he gives the tugboats their jobs for the day. Next door to this is Donald Dock.
Benjamin Bridge is a suspension bride that spans the harbour, based on the Angus L. Macdonald Bridge which connects Halifax and Dartmouth.
Willy's Island is a little island that is near the harbour mouth. Lilly Lighthouse and Bedford Buoy warn ships from hitting the island.
The Oceanic Institute is a research facility with a dock where Rebecca the Research Vessel lives.
The Fuel Dock
The fuel dock is near the Oceanic Institute. This is the place where the tugs fill with fuel.
The Oil Refinery is an industrial plant located on the shore of the Big Harbour where crude oil is refined into useful products. The tugboats often deliver oil barrels and pipes here. It is roughly based off of the Dartmouth Refinery which was closed in 2013.
The repair dock is where ships and boats get repaired if they break down or need their checkups. Shediac the Supply Shed lives here.
The container terminal is the place where ships come in and Clayton, the giant harbour crane lifts and loads containers.
The Harbour Master's Office is in a building near the entrance of the harbour. From here, the Harbour Master can view all of the ships that are entering. His office contains maps, a sonar, a radio to reach the Dispatcher, and his fish tank, which he is especially proud of. This is also the place from which he introduces the story in each episode.
The Junk Dock, named Jasper, is where Guysborough lives. The Junk Dock is the location where all of the harbour's garbage is taken.
Dock No. 9 is a dock where the old junk barge is located.
Citadel Hill is located on the Halifax side of the harbour. This is where the Clock Tower lives.