William John Loucks (26 June 1873 – 2 September 1968) was a Conservative member of the House of Commons of Canada.
He was born in Battersea, Ontario and became a farmer.
Loucks attended schools at Battersea and Kingston.
For 15 years, he served as president of the Delisle Telephone Company.
After serving a term in the 17th Canadian Parliament, Loucks was defeated by Major James Coldwell of the Co-operative Commonwealth Federation in the 1935 federal election, after riding boundaries were changed to replace the Rosetown riding with the new Rosetown—Biggar electoral district.