Perkumpulan rahasia adalah sebuah kelompok atau organisasi yang kegiatan, acara, fungsi dalam, atau keanggotaannya tertutup dari non-anggota. Perkumpulan tersebut dapat atau tak dapat berniat untuk membongkar keberadaannya. Istilah tersebut biasanya dipakai khusus untuk kelompok-kelompok tertutup, seperti badan intelijensi atau pemberontak gerilya, yang menyembunyikan kegiatan dan keanggotaan mereka tetapi memberi tekanan masyarakat.

• Heckethorn, Charles William (1886). The Secret Societies of All Ages and Countries, Embracing the Mysteries of Ancient India, China, Japan, Egypt, Mexico, Peru, Greece, and Scandinavia, the Cabbalists, Early Christians, Heretics, Assassins, Thugs, Templars, the Vehm and Inquisition, Mystics, Rosicrucians, Illuminati, Freemasons, Skopzi, Camorristi, Carbonari, Nihilists, and Other Sects (Edisi 2nd). Forgotten Books. ISBN 978-1-4400-8999-2.
• Whalen, William Joseph (1966). Handbook of Secret Organizations. Milwaukee: Bruce Pub. Co. LCCN 66026658.
• Axelrod, Alan (1997). The International Encyclopedia of Secret Societies and Fraternal Orders. New York: Facts on File. ISBN 0-8160-2307-7.
• Harwood, W. S. "Secret Societies in America," The North American Review, Vol. 164, No. 486, May, 1897.
• Hodapp, Christopher; Von Kannon, Alice (2008). Conspiracy Theories and Secret Societies For Dummies. Wiley. ISBN 0-470-18408-6.
• Jacob, Frank (2012). Geheimgesellschaften: Kulturhistorische Sozialstudien: Secret Societies: Comparative Studies in Culture, Society and History. Würzburg: Königshausen & Neumann. ISBN 978-3826049088.
• Kloosterman, Jaap (2013). Secret Societies. Leibniz Institute of European History (IEG).
• Roberts, J. M. (John Morris) (1972). The Mythology of the Secret Societies. New York: Scribner. ISBN 0-684-12904-3.
• Robbins, Alexandra (2004). Pledged: The Secret Life of Sororities. New York: Hyperion. ISBN 0-7868-8859-8.
• Stevens, Albert Clark (1899). The Cyclopædia of Fraternities. New York: Hamilton Printing & Publishing Company.
• Stephen Klimczuk, Gerald Warner (2009). Secret Places, Hidden Sanctuaries: Uncovering Mysterious Sights, Symbols, and Societies, New York: Sterling Publishing Company.

Lihat entri perkumpulan rahasia di kamus bebas Wikikamus.

Wikimedia Commons memiliki media mengenai Secret societies.

• Secret Societies: a very short history — Documents of Freemasons, Jesuits, Illuminati, Carbonari, Burschenschaften and other organizations
• Stevens, The cyclopædia of fraternities (2nd ed.). A dated review of the subject.
• Secret Societies in Australia and English Freemasonry