Geoffrey Bayldon
From Tardis Wiki, the free Doctor Who reference
Geoffrey Bayldon (born 7 January 1924) played Organon in the Doctor Who story The Creature from the Pit. He also voiced the Doctor in the Big Finish Doctor Who Unbound stories Auld Mortality and A Storm of Angels. Aged eighty years when the last was recorded, he is the oldest actor to play the Doctor in any medium to date. During the 1960s, he was considered for the roles of both the First and Second Doctors.
He was the longtime partner of fellow Doctor Who guest star Alan Rowe. He is best remembered as Catweazle in the 1970s ITV series of the same name.