Gordon Haddon Clark (August 31, 1902 – April 9, 1985) was an American philosopher and Calvinist theologian. He was a leading figure associated with presuppositional apologetics and was chairman of the Philosophy Department at Butler University for 28 years. He was an expert in pre-Socratic and ancient philosophy and was noted for defending the idea of propositional revelation against empiricism and rationalism, in arguing that all truth is propositional. His theory of knowledge is sometimes called scripturalism.