| Birthname: | John Marion Hart |
| Birth Date: | January 2, 1866 |
| Birth Place: | Prince Edward, Virginia, U.S. |
| Death Place: | Roanoke, Virginia, U.S. |
| State Senate: | Virginia |
| District: | 4th |
| Term Start: | January 8, 1908 |
| Term End: | April 8, 1914 |
| Preceded: | Archer A. Phlegar |
| Succeeded: | William L. Andrews |
| Party: | Democratic |
| Alma Mater: | Hampden–Sydney College |
| Spouse: | Caroline Overton Harris |
John Marion Hart (January 2, 1866 – December 12, 1955) was an American Democratic politician who served as a member of the Virginia Senate, representing the state's 4th district.[1] Hart resigned his seat in the Senate before the expiration of his second term in order to accept appointment as collector of internal revenue for the Western District of Virginia by President Woodrow Wilson.