The Boeing B-52 Stratofortress is a long-range, subsonic, jet-powered, strategic bomber operated by the United States Air Force (USAF) since 1955.

Beginning with the successful contract bid on 5 June 1946, the B-52 went through several design steps; from a straight wing aircraft powered by six turboprop engines to the final prototype YB-52, with eight turbojet engines. The aircraft made its first flight on 15 April 1952 with "Tex" Johnston as pilot.

Built to carry nuclear weapons for Cold War-era deterrence missions, the B-52 Stratofortress replaced the Convair B-36. Although a veteran of a number of wars, the Stratofortress has dropped only conventional munitions in actual combat. With the longest unrefueled range of any contemporary bomber, the B-52 carries up to 70,000 pounds (32,000 kg) of weapons.

The Air Force intends to keep the B-52 in service until at least 2040, an unprecedented length of service for a military aircraft. B-52s are periodically refurbished at the USAF maintenance depots such as Tinker Air Force Base, Oklahoma.

The USAF continues to rely on the B-52 because it remains an effective and economical heavy bomber, particularly in the type of missions that have been conducted since the end of the Cold War, mainly against nations that have limited air defense capabilities. The B-52's capacity to "loiter" for extended periods over (or even well outside) the battlefield, while delivering precision standoff and direct fire munitions, has been a valuable asset in conflicts such as Operation Enduring Freedom in Afghanistan.

The speed and stealth of the B-1 Lancer and B-2 Spirit have only been useful until enemy air defenses were destroyed, a task that has been swiftly achieved in recent conflicts. The B-52 boasts the highest mission capable rate of the three types of heavy bombers operated by the USAF. Whereas the B-1 averages a 53% ready rate, and the B-2 achieved a 26%, the B-52 averages 80% as of 2001

In September 2006, the B-52 became one of the first US military aircraft to fly using 'alternative' fuel. Syntroleum Corporation, a leader in Fischer-Tropsch process (FT) technology, announced that its Ultra-Clean jet fuel had been successfully tested in a B-52.

On 15 December 2006, tail number 61-0034, Wise Guy took off from Edwards with the synthetic fuel blend powering all eight engines, the first time an Air Force aircraft was completely powered by the mixture. The test flight was captained by Major General Curtis Bedke, commander of the Edwards Flight Test Center, the first time in 36 years that the installation's commander performed a first flight in a flight test program. The flight lasted seven hours, reached an altitude of 48,000 feet, and was considered a success

On 2–3 September 1996, two B-52H struck Baghdad power stations and communications facilities with 13 AGM-86C air-launched cruise missiles (ALCM) as part of Operation Desert Strike, a 34-hour, 16,000 statute mile round trip mission from Andersen AFB, on Guam—the longest distance ever flown for a combat mission. Only two days prior, the crews had completed a 17-hour flight from Louisiana to Guam.

Flying approximately 1620 sorties in the Gulf War, B-52s delivered 40% of the weapons dropped by coalition forces, while suffering only one aircraft loss, with several receiving minor damage from enemy action.