Arthur LeRoy Smith Sr. (February 13, 1886 – December 17, 1951) was a Canadian barrister, inventor and federal politician.

Smith first ran for a seat in the House of Commons of Canada as a Conservative candidate in the 1921 federal election in the East Calgary riding, he was defeated by William Irvine.

Smith filed a patent on an Air Heating System with the Canadian Intellectual Property Office on September 29, 1936.

This time he ran in the Calgary West riding in the 1945 federal election defeating four other candidates to win his first term in office.

He would run for re-election in the 1949 federal election winning his second term by a comfortable margin.