Born in Egypt, the actor made his first appearance as Brigadier Lethbridge-Stewart in 1968. He appeared alongside five incarnations of The Doctor, including Peter Davison and Tom Baker.
Courtney reprised the role in the 2008 series finale of The Sarah Jane Adventures. Despite being mentioned, he had not appeared in the main series since its 2005 revival.
He also made notable appearances in shows including The Bill, Only Fools and Horses and All Creatures Great And Small. In 2008 he appeared as the Archbishop of Canterbury alongside Ewan McGregor in Incendiary.
Courtney is survived by his second wife Karen and two children Philip and Bella.