Sir Crispin Charles Cervantes Tickell GCMG KCVO FZS[1] (25 August 1930 – 25 January 2022) was a British diplomat, environmentalist, and academic.

[1] He then had a posting at the British Embassy in The Hague (1955–58);[1] Mexico City (1958–61); London (1961–64); Paris (1964–70); and Private Secretary to various Chancellors of the Duchy of Lancaster (1970–72) during negotiations for the UK entry into the European Community.

He was appointed MVO in 1958 and later knighted as a KCVO in 1983 on the Royal Yacht Britannia, to mark the conclusion of Queen Elizabeth's Official Visit to Mexico.

When Clare Short, former international development secretary in Blair's Cabinet, said that British intelligence bugged the office of Kofi Annan, the UN Secretary-General, Tickell refused to comment on the accuracy of Short's claim, saying he had a continuing duty of loyalty to governments past and present and told the BBC, "What I would say is I would not be surprised if in New York there is a great deal of listening all over the place from one country to another, and I don't know whether it really makes very much difference.

Tickell also criticized Short for resigning from her position of Secretary for International Development in protest of Tony Blair's entry into the Iraq War in May 2003 and reprimanded her: "your prime loyalty is to your employer and, indeed, to the interests of the country.

"[4] Tickell was President of the Royal Geographical Society from 1990 to 1993 and Warden of Green College, Oxford, between 1990 and 1997, where he appointed George Monbiot and Norman Myers as Visiting Fellows.

[3] He was the president of the UK charity Tree Aid,[9] which enables communities in Africa's drylands to fight poverty and become self-reliant, while improving the environment.