Oscar Douglas Skelton (July 13, 1878 – January 28, 1941) was a Canadian professor, author, civil servant, and politician. He earned his M.A. from Queen's University in 1900, and his doctorate in political economy from the University of Chicago in 1908. He taught at Queen's University until 1925, where he also served in the university's administration. Skelton served as Chair of the university's board of trustees. He was the author of two books in the Chronicles of Canada series: The Day of Sir Wilfrid Laurier: A Chronicle of Our Own Times and The Railway Builders: A Chronicle of Overland Highways. He later became undersecretary of state for Foreign Affairs, replacing an aging Joseph Pope in 1925. He became one of Mackenzie King's most trusted advisors during the inter-war era. Skelton served as a member of the 2nd Council of the Northwest Territories until his death in 1941. His death, coming in the midst of wartime, hit Prime Minister King very hard; the two, who shared similar educational backgrounds, had been close. Historian John English, in his biography of Lester Pearson, wrote that Skelton played the major role in the building of Canada's External Affairs department.[1]