William McCartney Davidson (November 12, 1872 – March 23, 1942) was a Canadian journalist, politician, and author.

He defeated Conservative incumbent Samuel Bacon Hillocks by a comfortable margin to win to represent the North Calgary electoral district.

Davidson ran for election again as an Independent in a Calgary electoral district provincial by-election on January 15, 1923, held after the death of MLA Robert Edwards.

He was badly defeated, finishing a distant last behind Conservative Fred Davis, the winner, and Labor candidate William Irvine.

After he retired from provincial politics Davidson spent 2 years from 1926 to 1928 researching Louis Riel.