Thomas Whitten Slick (July 5, 1869 – January 3, 1959) was a United States federal judge.
Born in South Bend, Indiana, Slick received an LL.B. from the University of Michigan Law School in 1893. He was in private practice in South Bend from 1893 to 1925, serving as a prosecuting attorney of St. Joseph County, Indiana from 1896 to 1900 and as a city attorney of South Bend from 1918 to 1922.
On February 6, 1925, Slick was nominated by President Calvin Coolidge to a new seat on the United States District Court for the District of Indiana created by 43 Stat. 751. He was confirmed by the United States Senate on February 17, 1925, and received his commission the same day. On April 21, 1928, the District of Indiana was subdivided, and Slick was reassigned by operation of law to the newly created United States District Court for the Northern District of Indiana. Slick served in that capacity until his retirement from the bench on September 16, 1943.