Illinois's 3rd congressional district includes parts of Cook County and DuPage County, and has been represented by Democrat Delia Ramirez since January 3, 2023. Prior to being drastically reconfigured to a different region in 2023, when it was created largely out of portions from the 4th and 6th districts, the district was represented by Marie Newman from 2021 to 2023, Dan Lipinski from 2005 to 2021, and by Lipinski's father Bill from 1983 to 2005.