Thomas Day Singleton (Birth date unknown – November 25, 1833) was a 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.