The idea that esotericism is a form of “rejected knowledge” is back in vogue. This idea was also central to the so-called sociology of the occult of the 1970s, a research program that esotericism scholars have largely dismissed. Through a reassessment of this literature I argue that much of the criticism leveled at it missed the mark, and that mining it for theoretical resources can help us refine the field’s own undertheorized rejected knowledge narrative. In particular, the sociology of the occult offers useful tools for theorizing the historicity, substance, social significance, and social organization of esotericism as rejected knowledge.