Gérard de Ridefort (c. 1140 – 4 October 1189) was a Flemish crusader and the Grand Master of the Order of the Knights Templar from 1184 until his death.
Supporting Guy of Lusignan's side against Raymond III of Tripoli, his own personal enemy, the Grand Master contributed to the renewal of the war between Saladin and the Kingdom of Jerusalem. Having provided pretexts for the war, the Grand Master pushed the new King, Guy of Lusignan, in the Battle of Hattin, which was won by the Muslims and sealed the fall of the Christian Kingdom of Jerusalem.
Captured after the battle, Ridefort secured his release, although he was soon captured again and beheaded in 1189.