| Léon-Denis Gérin | |
| Office: | Member of the Legislative Assembly of Quebec for Stanstead |
| Successor: | Georges Vaillancourt |
| Term Start: | 1948 |
| Term End: | 1960 |
| Birth Date: | 6 June 1894 |
| Birth Place: | Sainte-Edwige-de-Clifton, Quebec |
| Death Place: | Coaticook, Quebec |
| Party: | Union Nationale |
Léon-Denis Gérin (June 6, 1894 - April 1, 1975) was a politician Quebec, Canada and a three-term Member of the Legislative Assembly of Quebec (MLA).
He was born on June 6, 1894, in Sainte-Edwidge-de-Clifton, Eastern Townships.
Gérin served as a city councillor from 1934 to 1935 and from 1942 to 1943 and as Mayor from 1944 to 1945 in Coaticook, Quebec.
He ran as a Union Nationale candidate in the provincial district of Stanstead in the 1948 provincial election and won. He was re-elected in the 1952 and 1956 elections.
Gérin was defeated in the 1960 election against Liberal candidate Georges Vaillancourt.
He died on April 1, 1975.