William Todd Tiahrt is an American politician who served as the U.S. representative for Kansas's 4th congressional district from 1995 to 2011. A member of the Republican Party, he was elected as part of the historic Republican Wave of 1994, defeating 18-year incumbent U.S. Representative Dan Glickman. He ran in 2010 for the United States Senate seat being vacated by Sam Brownback. He lost to fellow Republican U.S. Representative Jerry Moran of Hays, Kansas, 50%–45%.

Kansas's 4th congressional district is a congressional district in the U.S. state of Kansas. Based in the south central part of the state, the district encompasses the city of Wichita, the largest city in Kansas, three universities, Arkansas City, and the State of Kansas's only national airport.