The Alpha Jet TH (Phase 1) is a modernized variant of the Alpha Jet, undergoing a comprehensive upgrade to extend its service life and integrate it into modern data exchange systems. Initiated by the Royal Thai Air Force in 2020, with the participation of national companies, the modernization introduced a fully digital cockpit featuring multi-function displays (MFDs), a head-up display (HUD), and a new control panel. As part of Phase 1 modifications, the aircraft received updated avionics, improved communication systems, integration of the Link-T tactical data link, and partial integration of precision-guided munitions (PGMs) and air-to-surface missiles (ASMs). Full integration of these munitions is planned in subsequent upgrades up to Phase 2.

Introduced in Update "Storm Warning", the Alpha Jet TH (Phase 1) retains the core characteristics of the base model but has been given an expanded weapons arsenal. All-aspect AIM-9P4 air-to-air missiles are now available for self-defense against enemy aircraft; however, the aircraft has lost its internal cannon armament. Otherwise, the aircraft retains its strike capabilities, including the use of rockets, unguided bombs, and the ballistic computer for targeting.