T66

T66 may refer to:
 * T66 (rocket launcher), an American multiple rocket launcher
 * Avions Fairey T.66 Tipsy Nipper, a Belgian aerobatic aircraft
 * Ericsson T66, a mobile phone
 * Cooper T66, a racing car
 * Hawker Hunter T.66, a British-built trainer aircraft
 * INS Bitra (T66), a patrol vessel of the Indian Navy