Pituffik Space Base ( bee-doo-FEEK; Greenlandic: [pitufːik]) (IATA: THU, ICAO: BGTL), formerly Thule Air Base ( or ), is the United States Space Force's northernmost base, and the northernmost installation of the U.S. Armed Forces, located 1,210 km (750 mi) north of the Arctic Circle and 1,524 km (947 mi) from the North Pole on the northwest coast of Greenland. Pituffik's Arctic environment includes icebergs in North Star Bay, two islands (Saunders Island and Wolstenholme Island), a polar ice sheet, and Wolstenholme Fjord – the only place on Earth where four active glaciers join. The base is home to a substantial portion of the global network of missile warning sensors of Space Delta 4, and space surveillance and space control sensors of Space Delta 2, providing space awareness and advanced missile detection capabilities to North American Aerospace Defense Command (NORAD), the United States Space Force, and joint partners.

Pituffik Space Base is also home to the 821st Space Base Group and is responsible for space base support within the Pituffik Defense Area for the multinational population of "Team Pituffik". The base hosts the 12th Space Warning Squadron (12 SWS) which operates a Ballistic Missile Early Warning System (BMEWS) designed to detect and track ICBMs launched against North America. The base is also host to Detachment 1 of the 23rd Space Operations Squadron, part of the Space Delta 6's global satellite control network. The airfield's 3,000 m (10,000 ft) runway handles more than 3,000 US and international flights per year. The base is also home to the northernmost deep water port in the world. To assist with port operations, Pituffik is home to the only tugboat in the Department of the Air Force. In the summertime, the 71-foot tugboat escorts fuel tankers and cargo ships, aligns them with the pier, and moves icebergs out of the way as vessels enter North Star Bay.