A jet trainer is a jet aircraft for use as a trainer, whether for basic or advanced flight training. Jet trainers are either custom designs or modifications of existing aircraft. With the introduction of military jet-powered aircraft towards the end of the World War II it became a requirement to train pilots in the handling of such aircraft.

A trainer is a class of aircraft designed specifically to facilitate flight training of pilots and aircrews. The use of a dedicated trainer aircraft with additional safety features—such as tandem flight controls, forgiving flight characteristics and a simplified cockpit arrangement—allows pilots-in-training to safely advance their skills in a more forgiving aircraft.