| Thomas Day Singleton | |
| Birth Date: | unknown |
| Birth Place: | Kingstree, South Carolina |
| Death Date: | November 25, 1833 |
| Death Place: | Raleigh, North Carolina |
| Resting Place: | Congressional Cemetery, Washington, D.C. |
| State1: | South Carolina |
| District1: | 3rd |
| Term Start1: | March 4, 1833 |
| Term End1: | November 25, 1833 |
| Predecessor1: | Thomas R. Mitchell |
| Successor1: | Robert B. Campbell |
| Office2: | Member of the South Carolina House of Representatives |
| Term2: | 1826-1833 |
| Party: | Nullifier |
Thomas Day Singleton (Birth date unknown - November 25, 1833) was a slaveowner[1] and United States representative from South Carolina. He was born near Kingstree, South Carolina but his birth date is unknown.
Singleton was a member of the South Carolina House of Representatives, 1826-1833. He was elected as a Nullifier to the Twenty-third Congress and served without having qualified, from March 3, 1833, until his death in Raleigh, North Carolina, November 25, 1833, while en route to Washington, D.C. He was buried in the Congressional Cemetery, Washington, D.C.