| William A. Losier | |
| Office: | Member of the Legislative Assembly of New Brunswick |
| Term: | 1935–1944 |
| Constituency: | Gloucester |
| Birth Date: | 14 August 1896 |
| Birth Place: | Tracadie, New Brunswick |
| Death Place: | Tracadie, New Brunswick |
| Spouse: | Jeanne Salesse |
| Party: | New Brunswick Liberal Association |
| Occupation: | teacher, farmer |
| Children: | 8 |
William Arthur Losier (August 14, 1896 – April 8, 1952) was a Canadian politician. He served in the Legislative Assembly of New Brunswick as member of the Liberal party from 1935 to 1944.[1]