Pol III was a patrol boat of the Royal Norwegian Navy, used for guarding the inlet of the Oslofjord in early April 1940. She was a small vessel, originally a whaler, of 214 tons. She is best known for being the first Norwegian unit to engage the German invasion forces during the 1940 Operation Weserübung.

The Royal Norwegian Navy is the branch of the Norwegian Armed Forces responsible for naval operations of Norway, including those of the Norwegian Coast Guard. As of 2008, the Royal Norwegian Navy consists of approximately 3,700 personnel and 70 vessels, including 4 heavy frigates, 6 submarines, 14 patrol boats, 4 minesweepers, 4 minehunters, 1 mine detection vessel, 4 support vessels and 2 training vessels.