Thomas Alexander Varlan (born 1956) is a United States federal judge.
Born in Oak Ridge, Tennessee, Varlan received a B.A. from the University of Tennessee in 1978 and a J.D. from Vanderbilt University School of Law in 1981. He was in private practice in Atlanta, Georgia from 1981 to 1987. He was the law director for the City of Knoxville, Tennessee from 1988 to 1998, thereafter returning to private practice in Knoxville from 1998 to 2003.
On January 7, 2003, Varlan was nominated by President George W. Bush to a seat on the United States District Court for the Eastern District of Tennessee vacated by Robert Leon Jordan. Varlan was confirmed by the United States Senate on March 13, 2003, and received his commission on March 14, 2003.