Thomas L. Lewis (1866 – May 1, 1939) was a miner and president of the United Mine Workers of America (UMWA) from 1907 to 1911.

Born in Locust Gap, Pennsylvania in 1866, Lewis worked in the mines as a boy.

When Mitchell fell ill in 1907 and was unable to control the UMWA convention, Lewis led an attack on him and won the presidency.

Although Lewis stacked the organizing staff of the Mine Workers with his political supporters and turned the union's journal into a propaganda organ supporting his presidency, he did not retain leadership of the union after he signed regional wage agreements in 1909 and 1910 without the consent of the affected district presidents.

According to Winthrop Lane, Lewis also served as Secretary of the New River Coal Operator's Association.