UNTSO is an acronym for United Nations Truce Supervision Organization, an organization founded in 1948 for peacekeeping in the Middle East. Among its tasks are providing assistance to the United Nations Disengagement Observer Force (UNDOF) and the United Nations Interim Force in Lebanon (UNIFIL).

Its initial foundation was a result of Resolution 50 of the UN Security Council which was accepted on May 29, 1948.

Countries contributing military resources to UNTSO include, Argentina, Australia, Austria, Belgium, Canada, Chile, the People's Republic of China, Denmark, Estonia, Finland, France, Ireland, Italy, Nepal, Netherlands, New Zealand, Norway, Russia, Slovenia, Sweden, Switzerland and the USA. Notably no Islamic or Jewish country is included in this list.

UNTSO has offices in Beirut and Damascus, with its headquarters in Government House, Jerusalem.