| Honoré Mercier Jr. | |
| Office: | Member of the Legislative Assembly of Quebec for Châteauguay |
| Predecessor: | Hospice Desrosiers |
| Successor: | Auguste Boyer |
| Term Start: | 1908 |
| Term End: | 1936 |
| Predecessor2: | François-Xavier Dupuis |
| Successor2: | Hospice Desrosiers |
| Term Start2: | 1907 |
| Term End2: | 1908 |
| Birth Date: | 20 March 1875 |
| Birth Place: | Saint-Athanase, Quebec, Canada |
| Death Place: | Châteauguay, Quebec, Canada |
| Spouse: | Jeanne Fréchette |
| Party: | Liberal |
| Children: | Honoré Mercier III |
| Profession: | Lawyer |
Honoré Mercier Jr. (20 March 1875 – 19 June 1937) was a member of the Legislative Assembly of Quebec. He was the son of the former Quebec Premier Honoré Mercier and father of Honoré Mercier III.
Mercier was born in Saint-Hyacinthe, Quebec, and attended Collège Sainte-Marie and Université Laval law school. He was admitted to the Quebec Bar in 1900 and became a KC in 1913.
Mercier was a lawyer prior to his political career.
He was first elected in the 1904 Quebec general election for the Quebec Liberal Party, but was defeated in 1908. However, he was then elected in a 1908 by-election, and remained in the Legislative Assembly until 1936, when he did not run for re-election. He served in numerous Cabinet posts under Premiers Lomer Gouin and Louis-Alexandre Taschereau:
Besides his legal practice, Mercier was a member, director and headed of various organizations in Quebec:
Gérald Fauteux was his nephew.
He was honoured with the Knight (chevalier) of the Legion of Honour of France.