Sean Thomas Casten (born November 23, 1971) is an American businessman and politician serving as the U.S. representative for Illinois's 6th congressional district. The district covers southwestern Chicago, as well as many of Chicago's inner southwestern suburbs, such as Downers Grove, Wheaton, Lisle, Orland Park, and Western Springs. He is a member of the Democratic Party.

Due to redistricting as a result of the 2020 United States census, Casten and fellow Democrat Marie Newman competed to represent the same district in the 2022 Democratic primary election. Casten defeated Newman in the primary election on June 28, 2022. He won the general election, defeating the Republican nominee, Orland Park mayor Keith Pekau, on November 8, 2022.