The Boeing 777 is a long-range, wide-body, twin-engine jet airliner manufactured by Boeing Commercial Airplanes. It is the world's largest twinjet and is commonly referred to as the "Triple Seven".The aircraft has seating for over 300 passengers and has a range from 5,235 to 9,380 nautical miles (9,695 to 17,370 km), depending on model. Its distinguishing features include the largest-diameter turbofan engines of any aircraft, six wheels on each main landing gear, a circular fuselage cross-section, and blade-shaped tail cone. Developed in consultation with eight major airlines, the 777 was designed to replace older wide-body airliners and bridge the capacity difference between the 767 and 747. As Boeing's first fly-by-wire airliner, it has computer mediated controls; it is also the first entirely computer-designed commercial aircraft.

The 777 is produced in two fuselage lengths. The original 777-200 model first entered service in 1995, followed by the extended-range 777-200ER in 1997; the stretched 777-300, which is 33.3 ft (10.1 m) longer, began service in 1998. The longer-range 777-300ER and 777-200LR variants entered service in 2004 and 2006, respectively, while a freighter version, the 777F, debuted in 2009. Both longer-range versions and the freighter feature General Electric GE90 engines, as well as extended and raked wingtips. Other models are equipped with either the GE90, Pratt & Whitney PW4000, or Rolls-Royce Trent 800 engines. The 777-200LR is the world's longest-range airliner and holds the record for longest distance flown by a non-stop commercial aircraft, with the demonstrated capability to fly more than halfway around the world.

United Airlines first placed the 777 into commercial airline service in 1995. As of January 2012, 60 customers had placed orders for 1,242 aircraft of all variants, with 988 delivered.The most common variant used worldwide is the 777-200ER, with 415 aircraft delivered, and Emirates operates the largest 777 fleet, with 87 aircraft as of August 2011.The airliner has recorded two hull-loss accidents, with no occupant fatalities, as of December 2011.

Through the 2000s, the 777 has emerged as one of its manufacturer's best-selling models. Because of rising fuel costs, airlines have acquired the type as a comparatively fuel-efficient alternative to other wide-body jets and have increasingly used the aircraft on long-haul, transoceanic routes. Direct market competitors have included the Airbus A330-300, A340, and the upcoming A350. The subsequently developed 787 Dreamliner also shares design features with the 777.