Dennis Mahon is a white supremacist and anti-Semite who has been active in several states in the Midwest and in Arizona. He has held leadership positions within various white supremacist groups, including the Ku Klux Klan and White Aryan Resistance (WAR), a now-defunct group led by long-time white supremacist Tom Metzger.
Mahon has cultivated domestic and international alliances within extremist circles since the 1980s. He has also supported the activity of other white supremacist and anti-Semitic figures in the United States and abroad. Although he was active as an organizer and leader in the past, since the early 2000s, Mahon has maintained a low profile, staying out of the public eye.