The Fairchild Swearingen Metroliner or the Fairchild Aerospace Metro is a 19-seat, pressurised, twin turboprop airliner first produced by Swearingen Aircraft and later by Fairchild at a plant in San Antonio, Texas, United States.

The Fairchild Metro was created in the late 1960s specifically to serve the emerging regional airline market. It was developed as a stretched version of Swearingen's Merlin II corporate turboprop, which was introduced in 1965. Regular production of the Metro began in 1971, the same year Fairchild acquired Swearingen. The Metro was the regional airliner first used by many of the most successful regional airlines of the 1970s and 1980s, including Skywest Airlines, Horizon Airlines, Comair and Wings West.

The SA227-AC Metro III was initially certified in 1980 at up to 14,000 pounds (6,350 kg) this increasing to 14,500 pounds (6,577 kg) as engines and structures were upgraded. An option to go as high as 16,000 pounds (7,257 kg) was offered. Externally, improvements incorporated into the Metro III were a 10 ft (3.05 m) increase in wing span, four-bladed props, redesigned "quick-access" engine cowlings and numerous drag-reducing airframe modifications, including landing gear doors that close after the gear is extended.

Over the years, a total of 331 Merlins, 117 Merlin IVs and 605 Metros would be built.