| Ernest Duke | |
| Birth Date: | 21 December 1880 |
| Death Place: | Victoria, British Columbia |
| Birth Place: | Mono Mills, Albion Township, Peel County, Ontario |
| Office: | Member of the Legislative Assembly of Alberta |
| Constituency: | Rocky Mountain |
| Term Start: | 1935 |
| Term End: | 1940 |
| Predecessor: | George Edward Cruickshank |
| Successor: | District abolished |
| Constituency2: | Pincher Creek-Crowsnest |
| Term Start2: | 1940 |
| Term End2: | 1948 |
| Predecessor2: | District established |
| Successor2: | William Kovach |
| Party: | Social Credit |
Lawrence Ernest Oscar Duke (December 21, 1880 - January 19, 1954) was a provincial politician from Alberta, Canada. He served as a member of the Legislative Assembly of Alberta from 1935 to 1948, sitting with the Social Credit caucus in government.[1]