John Wayne Cox Jr. is an American politician and attorney who served a single term as a Democratic member of the United States House of Representatives representing Illinois's 16th congressional district.

The 16th congressional district of Illinois is represented by Republican Darin LaHood. Prominent past representatives from the 16th district have included Everett Dirksen, who went on to become the Republican leader in the United States Senate; John B. Anderson, who became the 3rd highest ranking Republican in the House and went on to run as a major independent candidate in the 1980 Presidential election; and Lynn Martin, who later served as United States Secretary of Labor.