John Kenneth Blackwell (born February 28, 1948) is an American politician, author, and conservative activist who served as the mayor of Cincinnati, Ohio (1979–80), the Ohio State Treasurer (1994–99), and Ohio Secretary of State (1999–2007). He was the Republican candidate for governor of Ohio in 2006, the first African-American major-party candidate for governor of Ohio. He is a Senior Fellow for Family Empowerment with The Family Research Council.