Geoffrey Allan Crossley, CMG (11 November 1920 – 13 June 2009) was a British diplomat, ambassador to Colombia and to the Holy See.
Crossley was educated at Penistone Grammar School and Gonville and Caius College, Cambridge.
During the Second World War he served in the Ministry of Supply (1941) and the Foreign Office (1942) and subsequently in Algeria and France.
He was a Political Officer (later in charge of the Political Department) in the Middle East Command, later the Near East Command, Cyprus, 1959–61; Head of Chancery at Bern 1961–65; on secondment to the Ministry of Overseas Development as Head of the West and North Africa Department 1965–67; Deputy High Commissioner, Lusaka, 1967–69; and Counsellor, Oslo, 1969–73.
After retiring from the Diplomatic Service, Crossley was Director, External Relations and Continuing Education, European Institute of Business Administration (INSEAD), Fontainebleau, 1980–84.