Thomas Todd was an Associate Justice of the Supreme Court of the United States from 1807 to 1826. Raised in the Colony of Virginia, he studied law and later participated in the founding of Kentucky, where he served as a clerk, judge, and justice. He was married twice and had a total of eight children. Todd joined the U.S. Supreme Court in 1807 and his handful of legal opinions there mostly concerned land claims. He was labeled the most insignificant U.S. Supreme Court justice by Frank H. Easterbrook in The Most Insignificant Justice: Further Evidence, 50 U. Chi. L. Rev. 481 (1983).

An associate justice of the Supreme Court of the United States is a justice of the Supreme Court of the United States, other than the chief justice of the United States. The number of associate justices is eight, as set by the Judiciary Act of 1869.