Karl Germer (22 January 1885 – 25 October 1962) was 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.
As author and occultist Aleister Crowley’s representative in Germany, Germer moved to America after being released from Nazi confinement (he was jailed for being an associate of the "High Grade Freemason Aleister Crowley"). In 1942, Crowley appointed Germer as his successor as OHO, the office he filled after Crowley's death in 1947.