| Honorific-Prefix: | The Honourable |
| William George Clark | |
| Order: | 19th |
| Office: | Lieutenant Governor of New Brunswick |
| Term Start: | March 5, 1940 |
| Term End: | November 1, 1945 |
| Predecessor: | Murray MacLaren |
| Successor: | David Laurence MacLaren |
| Governor General: | The Earl of Athlone |
| Premier: | Allison Dysart John B. McNair |
| Birth Date: | 1 October 1865 |
| Birth Place: | Queensbury, New Brunswick |
| Death Place: | Fredericton, New Brunswick, Canada |
| Nationality: | Canadian |
| Party: | Liberal |
| Alma Mater: | University of New Brunswick |
| Occupation: | Merchant |
| Profession: | Politician |
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.
Father of historian Esther Clark Wright.