The ATR 42 is a regional airliner produced by Franco-Italian manufacturer ATR, with final assembly in Toulouse, France. On 4 November 1981, the aircraft was launched with ATR, as a joint venture between French Aérospatiale (now Airbus) and Aeritalia (now Leonardo S.p.A.). The ATR 42-300 performed its maiden flight on 16 August 1984 and type certification was granted during September 1985. Launch customer Air Littoral operated its first revenue-earning flight in December of that year. The high-wing airliner is powered by two turboprop engines, Pratt & Whitney Canada PW120s. The number "42" in its name is derived from the aircraft's original standard seating capacity of 42 passengers. Later variants are upgraded with new avionics, a glass cockpit, and newer engine versions. The ATR 42 is the basis for the stretched ATR 72, introduced in October 1989.

The ATR 72 is a twin-engine turboprop, short-haul regional airliner developed and produced in France and Italy by aircraft manufacturer ATR (French: Avions de transport régional or Italian: Aerei da Trasporto Regionale), a joint venture formed by French aerospace company Aérospatiale (now Airbus) and Italian aviation conglomerate Aeritalia (now Leonardo S.p.A.). The number "72" in its name is derived from the aircraft's typical standard seating capacity of 72 passengers. During the 1980s, French aerospace company Aérospatiale and Italian aviation conglomerate Aeritalia merged their work on a new generation of regional aircraft. A new jointly owned company, ATR, was established to develop, manufacture, and market their first airliner, which was later designated as the ATR 42. On 16 August 1984, the first model of the series, designated as the ATR 42-300, performed the type's maiden flight. During the mid-1980s, the ATR 72 was developed as a stretched variant of the ATR 42. On 27 October 1989, Finnish airline Finnair became the first airline to operate the type in revenue service. The ATR 72 has also been used as a corporate transport, cargo aircraft, and maritime patrol aircraft.

To date, all of the ATR series have been completed at the company's final assembly line in Toulouse, France; ATR benefits from sharing resources and technology with Airbus SE, which has continued to hold a 50% interest in the company. Successive models of the ATR 72 have been developed. Typical updates have included new avionics, such as a glass cockpit, and the adoption of newer engine versions to deliver enhanced performance, such as increased efficiency and reliability and reductions in operating costs. The aircraft share a high degree of commonality with the smaller ATR 42, which remains in production as of January 2023.