Ramstein Air Base, or Ramstein AB (IATA: RMS, ICAO: ETAR), is a United States Air Force base located in Rhineland-Palatinate, a state in southwestern Germany. It serves as the headquarters for the United States Air Forces in Europe – Air Forces Africa (USAFE-AFAFRICA) and NATO Allied Air Command (AIRCOM). Ramstein is near the town of Ramstein-Miesenbach, which is situated outside the base's west gate, in the rural district of Kaiserslautern. The base supports forward elements deploying to Eastern Europe and Africa.

The construction of the air base was a project designed and undertaken by the French Army and the U.S. Army Corps of Engineers from 1949 to 1952.

Ramstein AB is part of the Kaiserslautern Military Community (KMC), where more than 54,000 American service members and over 5,400 U.S. civilian employees live and work. U.S. organizations in the KMC also employ the services of more than 6,200 German workers. Air Force units in the KMC alone employ almost 9,800 military members, who are accompanied by nearly 11,100 family members. There are more than 16,200 military personnel, U.S. civilians, and U.S. contractors assigned to Ramstein AB alone.

The east gate of Ramstein Air Base is approximately 16 kilometres (10 mi) from Kaiserslautern (locally referred to by Americans as "K-Town").