Karl Johannes Germer (22 January 1885 – 25 October 1962), also known as Frater Saturnus, was a German occultist and the United States representative and later a successor of author and occultist Aleister Crowley as the Outer Head of the Order (OHO) of Ordo Templi Orientis from 1947 until his death in 1962.
He was born in Elberfeld, Germany and died in West Point, California.