William Ashbury Buchanan, (born: July 2, 1876 South Monaghan, Ontario died: July 12, 1954) was a journalist, publisher and politician based in Alberta.
Following a career as a journalist in Ontario, Buchanan moved to Alberta and purchased the Lethbridge Weekly Herald in 1905. He attempted, unsuccessfully, to turn the paper into a daily in 1907 but it soon resumed a weekly publishing schedule.
Buchanan entered provincial politics when he contested the riding of Lethbridge City on behalf of the Alberta Liberal Party in the 1909 provincial election and won a seat in the Alberta Legislature. He switched to federal politics in the 1911 federal election and was elected for the seat of Medicine Hat as a federal Liberal.
As a result of the Conscription Crisis of 1917, Buchanan crossed the floor to support the government of Sir Robert Laird Borden. He was re-elected to the Canadian House of Commons as a Unionist for the new riding of Lethbridge in the 1917 general election. He did not run in the 1921 election.