The Aermacchi MB 339 is an Italian military trainer and light attack aircraft a development of the MB 326.

The MB 339 is of conventional configuration, and shares much of the 326's airframe. It has a low, un-swept wing with tip tanks and jet intakes in the roots, tricycle undercarriage, and accommodation for the student and instructor in tandem. The most significant revision was a redesign of the forward fuselage to raise the instructor's seat to allow visibility over and past the student pilot's head.

The first flight took place on August 12, 1976 and deliveries to the Italian Air Force commenced in 1979. Still in production in 2004 in an enhanced version with a much-modernised cockpit. Over 200 MB 339s have been built, with roughly half of them going to the Italian Air Force.

The MB-339A, equipped with a Viper 632 engine, is in service with seven air forces in basic and advanced training and close air support roles. The MB-339B is fitted with the more powerful Viper 680 Rolls-Royce engine and higher capacity tip tanks

The MB-339C, also powered by the Viper 680 engine, is fitted with an enhanced avionics fit. The aircraft has been in full service since 1991 and its configuration includes: head-up display (HUD) in both cockpits; a monochromatic multifunction display (MFD); hands on throttle and stick (HOTAS) control; NAV computer; weapon-aiming computer; inertial platform; stores management system and radar warning receiver.

The MB-339 has the capability to carry a wide variety of US and Nato standard external stores under six wing hardpoints.

The MB-339CD is equipped with an electronic warfare suite including an Elettronica ELT-156 radar warning receiver, BAE Systems Integrated Defense Solutions (formerly Tracor) AN/ALE-40 chaff and flares dispensing system and Elettronica ELT-555 active electronic countermeasures (ECM) deception pod.