This article examines John T. Clark, a relatively little-known but influential figure in the rise of fundamentalism among the Latter-day Saints during the early twentieth century. By 1921, small groups of excommunicated polygamists had begun to congregate at homes, offices, industrial buildings, and even in open-air settings. While no identifiable leaders would emerge until the 1930s, these groups would eventually coalesce to form the fundamentalist movement. Several individuals, including Clark, became prominent within the informal gatherings, either because of their testimonies, convictions, publications, financial successes, or claims to priesthood authority. Clark is unusual, however, because he was apparently never a polygamist. Rather, it was his doctrinal unorthodoxy and creative theological speculations that distanced him from the official LDS Church and made him an appealing figure to others whose ideas included the continuation of post-Manifesto polygamy.