| Moreau S. Crosby | |
| Office1: | 22nd Lieutenant Governor of Michigan |
| Governor1: | David Jerome Josiah Begole |
| Term Start1: | January 1, 1881 |
| Term End1: | January 1, 1885 |
| Predecessor1: | Alonzo Sessions |
| Successor1: | Archibald Buttars |
| State Senate2: | Michigan |
| District2: | 28th |
| Term Start2: | 1873 |
| Term End2: | 1874 |
| Predecessor2: | John C. Dexter |
| Successor2: | Lyman Murray |
| Birth Date: | 2 December 1839 |
| Birth Place: | Manchester, New York |
| Death Place: | Boston, Massachusetts |
| Party: | Republican |
Moreau S. Crosby (December 2, 1839 – September 12, 1893) was an American politician who served in the Michigan Senate from 1873 to 1874 and as the 22nd lieutenant governor of Michigan from 1881 to 1885.[1] [2] [3] he died at age 53 in Boston.