The sixth season of British science fiction television series Doctor Who began on 10 August 1968 with the first story of season 6 The Dominators and ended Patrick Troughton's reign as the Doctor with its final story The War Games.

Patrick Troughton, Frazer Hines and Wendy Padbury make their final regular appearances as the Second Doctor, Jamie McCrimmon and Zoe Heriot respectively.

Troughton and his fellow actors collectively decided that the workload of Doctor Who was exhausting them, and that they would soon depart from the show.

This compares to the first two seasons of the Second Doctor from which only two complete serials (The Tomb of the Cybermen and The Enemy of the World) survive.

Both of these would be beaten in 1986 by the 14-part season-spanning story The Trial of a Time Lord The Dominators and The Mind Robber were both produced at the end of the fifth recording block and held over to Season 6.