Reformed fundamentalism (also known as fundamentalist Calvinism) arose in some conservative Presbyterian, Congregationalist, Reformed Anglican, Reformed Baptist, Non-denominational and other Reformed churches, which agrees with the motives and aims of the broader evangelical Protestant fundamentalism. The movement was historically defined by a repudiation of liberal and modernist theology, the publication (1905-1915) entitled, The Fundamentals, and had the intent to progress and revitalise evangelical Protestantism in predominantly English-speaking Protestant countries, as well as to reform separated churches according to the Bible, historic expression of faith and the principles of the Reformation. The Fundamentalist–Modernist controversy, and the Downgrade controversy, kindled the growth and development of reformed fundamentalism in the United States and the United Kingdom. Reformed fundamentalists have laid greater emphasis on historic confessions of faith, such as the Westminster Confession of Faith. Sixteenth century Reformers such as John Calvin, Martin Luther, John Knox, Theodore Beza, Philip Melanchthon and Protestant ministers such as Matthew Henry, John Gill, John Bunyan, George Whitefield, Jonathan Edwards, Charles Spurgeon, J. C. Ryle, John Burgon, F. B. Meyer, Dwight L. Moody, George Müller and G. Campbell Morgan have shaped the leaders in this reformed tradition.

Some of the recent and better-known leaders who have described themselves as both Calvinist and fundamentalist have been Carl McIntire of the American Bible Presbyterian Church, Ian Paisley of the Northern Irish Free Presbyterian Church of Ulster, Thomas Todhunter Shields of Jarvis Street Baptist Church, D. James Kennedy of Coral Ridge Presbyterian Church, and J. Oliver Buswell of Wheaton College. Other evangelicals with connections to reformed fundamentalism would be J. Gresham Machen, O. T. Allis, Chester E. Tulga, Arthur Pink, E. J. Poole-Connor, Martyn Lloyd-Jones, J. I. Packer, and R. C. Sproul.

The Free Presbyterian dictum, "we preach Christ crucified" (1 Corinthians 1.23), is a unifying Christocentric maxim for those in the movement. Reformed fundamentalists have sought to maintain the authority and accuracy of the Bible, the doctrines of grace, purity of doctrine and the unique person of Jesus Christ. Fundamental Reformed liturgical praxis emphasizes the practices of congregational singing and head covering. It teaches the importance of family prayer in the home.