| Thomas J. Deadrick | |
| Office1: | Speaker of the South Dakota House of Representatives |
| Term Start1: | January 2007 |
| Term End1: | January 2011 |
| Predecessor1: | Matthew J.W. Michels |
| Successor1: | Valentine Rausch |
| State House2: | South Dakota |
| State: | South Dakota |
| District2: | 21st |
| Term Start2: | 2003 |
| Term End2: | 2011 |
| Birth Date: | August 26, 1952 |
| Profession: | Attorney |
| Party: | Republican |
Thomas J. Deadrick is a former Republican member of the South Dakota House of Representatives, representing the 21st District from 2003 and 2011. He also served as the Speaker of the House. His district included Brule, Buffalo, Charles Mix, Jones and Lyman counties.