Sir Colville Adrian de Rune Barclay KCMG CB CBE MVO PC (17 September 1869 – 2 June 1929) was a British diplomat who served as chargé d'affaires in Washington D.C., minister to Sweden and Hungary and ambassador to Portugal.
In 1897 he was transferred to the embassy in Paris where for five years he was private secretary to the ambassador, Sir Edmund Monson.
From Paris, Barclay was posted to Rio de Janeiro, Bucharest, Sofia and Belgrade before being promoted in 1913 to be Counsellor at the embassy at Washington, D.C. where he remained throughout the First World War; towards the end of the war he was chargé d'affaires in the absence of the ambassador, Lord Reading.
Colville Barclay was appointed MVO while serving in the British Embassy in Paris in 1903 when King Edward VII visited that city.
[6] He was knighted KCMG in the 1922 New Year Honours[7] and was made a Privy Counsellor in June 1928[8] on his appointment to Portugal.