Thomas Jefferson Barr (1812 – March 27, 1881) was an American politician and a U.S. Representative from New York, serving one term from 1859 to 1861.

Barr moved to Scotch Plains, New Jersey in 1835, and conducted a roadhouse.

Elected on January 6, 1859, as an Independent Democrat to the 35th United States Congress to fill the vacancy caused by the resignation of John Kelly, and was re-elected to the 36th United States Congress, Barr was U.S. Representative for the fourth district of New York and held office from January 17, 1859, to March 3, 1861.

Subsequently, he was employed in the office of the Collector of the Port of New York.

He is interred at Calvary Cemetery, Woodside, New York.