William George Clark (October 1, 1865 – January 18, 1948) was a merchant and political figure in New Brunswick, Canada. He represented York—Sunbury in the House of Commons of Canada from 1935 to 1940 as a Liberal member. Clark was the 19th Lieutenant Governor of New Brunswick from 1940 to 1945. He was born in Queensbury, New Brunswick. Clark served as a town councillor for Fredericton Town Council from 1917 to 1925 and was mayor from 1925 to 1935.