John Mondy Shimkus (, born February 21, 1958) is an American politician who served as a U.S. representative from 1997 to 2021, representing the 20th, 19th and 15th congressional districts of Illinois. Shimkus is a member of the Republican Party. On August 30, 2019, he announced that he would not seek re-election for his seat in 2020 and was succeeded by fellow Republican Mary Miller.