The M-346 Master began life as a co-development between Alenia Aermacchi with Russia's Yakovlev known as the Yak/AEM-130 but both companies decided to go their separate ways in the year 2000; Yakovlev eventually designing the Yak-130. The M-346 was designed to replace the MB.339 in the training role, but also to offer light attack capability which would make it attractive in the export markets. For this purpose, the M-346 is an incredibly cost-effective aircraft, reportedly with flying hour costs just one-tenth of that of the Eurofighter Typhoon. Despite this, the M-346 features many advanced features found in 4th and 4.5 generation aircraft including a digital fly-by-wire system, an all-glass cockpit with HOTAS controls and an optional helmet-mounted display. The avionics set is designed to ease the transition into more advanced aircraft like the Typhoon or Gripen, and can mimic a variety of electronic warfare systems. The twin Honeywell engines are also capable of transonic speeds, which compensates for the lack of afterburner. For light attack missions, the M-346 can carry a variety of air-to-air and air-to-ground stores as well as defensive electronic equipment. Fuel tanks as well as a removable refueling probe can also be fitted. Aside from its main user, the Aeronautica Militare, the M-346 has been exported to Israel, Poland, and Singapore, with a number of other orders being negotiated. Notably, it is under contention for the lucrative USAF T-X program.

First flight of the M-246 prototype took place on 15 July 2004, but entry into Italian service would take over a decade, until 2015. The basic version for the Aeronautica Militaire is known as the T-346A and is used exclusively in the trainer role. Other variants include the M-346LCA (Light Combat Aircraft) for Poland, as well as proposed multi-role versions M-346FT (Fighter Trainer) and M-346FA (Fighter Attack). It is known as the T-100 in the USAF's T-X trainer program.