Jerry Francis Costello (born September 25, 1949) is the former U.S. Representative for Illinois's 12th congressional district. He previously represented Illinois's 21st congressional district, and served in Congress from 1988 to 2013. He is a member of the Democratic Party and was the dean of Illinois's 21-member congressional delegation. In October 2011, Costello announced that he would not seek another term in Congress in 2012. He was succeeded by William Enyart.