William "Bill" Edgar is an American apologist and was professor of apologetics at Westminster Theological Seminary. He has been called by Charles Colson "one of evangelicalism's most valued scholars and apologists".

Westminster Theological Seminary (WTS) is a Protestant theological seminary in the Reformed theological tradition in Glenside, Pennsylvania. It was founded by members of the faculty of Princeton Theological Seminary in 1929 after Princeton chose to take a liberal direction during the Fundamentalist–Modernist controversy.