Although at first glance nearly identical to the CH-46 which preceded it, the Boeing Vertol CH-47 Chinook is in reality a considerably different and larger aircraft built for the specific requirements of the US Army. It shares its predecessor's tandem twin-rotor configuration but has an enlarged fuselage with prominent side fairings, giving it a more bulky appearance, an enlarged rotor diameter, and a fixed quadricycle landing gear. Neverthless, the CH-47's far superior lift capacity over the CH-46 is mainly due to its significantly more powerful Lycoming engines (one alone having a higher power rating than the CH-46) making it the main heavy helicopter in the US Army's arsenal capable of airlifting 155-mm howitzers and other large equipment for infantry and airborne units. A small number are also used for special operations while others have been exported to over 20 countries and civilian operators, notably the United Kingdom and Japan (built locally by Kawasaki). US and UK Chinooks have seen extended action in Vietnam, the Falklands, the Gulf War and the current conflicts in Afghanistan and Iraq and will likely remain in active service well into the 21st century.

The Chinook was developed from the Vertol Model 114 which was basically an enlargened version of the Model 107. The first prototype to fly was the YCH-1B which took to the air on 21 September 1961, entering service as the CH-47A. Modified rotor blades were later installed in the CH-47B while further upgrades led to the CH-47C with more powerful engines and increased fuel and to which a number of earlier units were converted to. The definitive Army variant, however, is the CH-47D with significant airframe improvements, a new engine and transmission, a modernized flight deck and advanced avionics including GPS guidance. Other versions include the MH-47E for special operations (including armor, armament, and an inflight-refuelling probe) and the Model 414 marketed for export. UK variants are designated Chinook HC.1 (CH-47C) and HC.2 (CH-47D) while a planned HC.3 for special operations is based on the MH-47E.