Thomas Willis Cobb (1784 – February 1, 1830) was a United States representative and Senator from Georgia.

Born in Columbia County, Georgia, he pursued preparatory studies, and studied law. He was admitted to the bar and practiced in Lexington, Georgia. He moved to Greensboro and was elected as a Representative to the Fifteenth and Sixteenth Congresses, serving from March 4, 1817, to March 3, 1821. He was an unsuccessful candidate for reelection to the Seventeenth Congress, but was elected to the Eighteenth Congress and served from March 4, 1823, to December 6, 1824, when he resigned, having been elected to the U.S. Senate; while a Representative during the Eighteenth Congress, he was chairman of the Committee on Public Expenditures. He was elected to the Senate to fill the vacancy caused by the death of Nicholas Ware and served from December 6, 1824, until his resignation in 1828. The press announced that he would "probably resign" in August 1828,^[1] and his successor, Oliver H. Prince, took office in November 1828.^[2] Cobb was a judge of the superior court of Georgia, and died in Greensboro in 1830. Cobb County, Georgia is named in his honor and its county seat, Marietta, is named for his wife Mary.^[3] He was a slaveowner and the cousin of Confederate Generals Thomas Reade Rootes Cobb and Howell Cobb.^[4]