Stephen Anthony McNallen is an American proponent of Heathenry, a modern Pagan new religious movement, and a white nationalist activist. He founded the Asatru Folk Assembly (AFA), which he led from 1994 until 2016, having previously been the founder of the Viking Brotherhood and the Asatrú Free Assembly.

The Asatru Folk Assembly (AFA) is a white nationalist international Ásatrú organization, founded by Stephen A. McNallen in 1994. Many of the assembly's doctrines, heavily criticized by most heathens, are based on ethnicity, an approach it calls "folkish". Once headquartered in Grass Valley, California, with chapters worldwide, the AFA is recognized as a 501(c)(3) nonprofit religious organization.