What was the name of the first commercial jet airliner, introduced in 1952?

The first commercial jet airliner, introduced in 1952, was the de Havilland Comet.

Built in Britain by de Havilland, the four-engine DH.106 Comet first flew on July 27, 1949. It entered scheduled service with British Overseas Airways Corporation (BOAC) on May 2, 1952, carrying fare-paying passengers from London to Johannesburg. Its pressurized cabin, swept wings, quiet ride and high cruising altitude made jet travel seem revolutionary compared with piston-engine airliners.

The Comet’s early lead was later overshadowed by serious structural-fatigue failures involving its square-cornered cabin windows. The aircraft was withdrawn, redesigned and eventually returned as the more successful Comet 4. The Boeing 707 and Douglas DC-8 became the dominant long-range jets, but they followed the Comet rather than preceding it. The Sud Aviation Caravelle was another early jetliner, but it entered service later, in 1959.