Peter John Visclosky ( vih-SKLOSS-kee; born August 13, 1949) is an American politician who served as the U.S. representative for Indiana's 1st congressional district from 1985 until his retirement in 2021. He is a member of the Democratic Party and was the dean of the Indiana congressional delegation before his retirement in 2021. The District lies in Northwest Indiana, and includes most of the Indiana side of the Chicago metropolitan area. Redistricting passed by the Indiana General Assembly in 2011 changed the district's boundaries, effective January 2013, to include all of Lake and Porter counties as well as the western and northwestern townships of LaPorte County, while shifting Benton, Newton, and Jasper counties out of the district.
On November 6, 2019, Visclosky announced that he would not seek re-election in 2020.