Thomas Bryant Cotton (born May 13, 1977) is an American politician, attorney, and former military officer serving as the junior United States senator from Arkansas since 2015. A member of the Republican Party, he served in the U.S. House of Representatives from 2013 to 2015. Cotton was elected as the U.S. representative for Arkansas's 4th congressional district in 2012 and to the Senate at age 37 in 2014, defeating two-term Democratic incumbent Mark Pryor.