| Jack Yost | |
| State Senate: | West Virginia |
| District: | 1st |
| Term Start: | January 14, 2009 |
| Term End: | January 11, 2017 |
| Preceded: | Andy McKenzie |
| Succeeded: | Ryan Weld |
| State Delegate2: | West Virginia |
| District2: | 2nd |
| Term Start2: | January 8, 2003 |
| Term End2: | January 14, 2009 |
| Birth Date: | 12 October 1945 |
| Birth Place: | Weirton, West Virginia, U.S. |
| Party: | Democratic |
| Spouse: | Kris Littell |
| Residence: | Wellsburg, West Virginia, U.S. |
| Alma Mater: | West Liberty State College |
| Birth Name: | Harold Jackson Yost Jr. |
Harold Jackson Yost Jr. (born October 12, 1945) is a former Democratic member of the West Virginia Senate, representing the 1st district between 2008 and 2016.