[1][2] Collis was educated at King Edward VII School, Sheffield, from 1967 until 1973 and at Christ's College, Cambridge.

He joined Her Majesty's Diplomatic Service in 1978 and served his first posting as Second Secretary in Bahrain from 1981 to 1984.

From 1984– 1986 he served as Middle East Spokesman in the News Department of the Foreign and Commonwealth Office.

[3][4] He presented his credentials as British Ambassador to Saudi Arabia on 3 February 2015.

[1][8] After leaving the diplomatic service, Collis took on roles at FMA, a consultancy founded by Francis Maude and Simone Finn; and at Sovereign Strategy, a political consulting and PR firm.