| class="wikitable sortable |
| Name (English / local (abbreviation)) | Founded | Region served | Notes |
|---|
| Association against Quackery / Vereniging tegen de Kwakzalverij (VtdK) | 1881 | {{NLD}} | Oldest skeptical organisation.[{{Cite news |url=http://www.quackometer.net/blog/2009/08/dutch-sceptics-have-bogus-libel.html |title=Dutch Sceptics Have 'Bogus' Libel Decision Overturned On Human Rights Grounds |author=Andy Lewis |publisher=The Quackometer |date=3 August 2009 |accessdate=16 May 2014}}] Member of ECSO.{{citation needed|reason=Not sure if VtdK is a member, but their chairwoman Catherine de Jong also serves on the ECSO board.|date=July 2014}} |
| Association for Skeptical Enquiry (ASKE) | 1997 | {{UK}} | Member of ECSO.[{{Cite web|url=http://www.ecso.org/member-org |title=Skeptics Organisations: ECSO Members |work=ECSO website |publisher=European Council of Skeptical Organisations |date=16 March 2008 |accessdate=19 July 2014 |url-status=dead |archiveurl=https://web.archive.org/web/20140927094904/http://www.ecso.org/member-org |archivedate=27 September 2014 }}] |
| Australian Skeptics | 1980 | {{AUS}} | |
| Center for Inquiry (CFI) | 1991 | File:Apollo17earth white.jpg World | Global umbrella organisation based in Amherst, New York. |
| Committee for the Advancement of Scientific Skepticism (CASS) | 2010 | {{CAN}} | Part of Centre for Inquiry Canada. |
| Committee for Skeptical Inquiry (CSI), formerly Committee for the Scientific Investigation of Claims of the Paranormal (CSICOP) | 1976 | {{USA}} | Part of the Center for Inquiry. |
Committee Para / Comité Para[Its full name, Comité Belge pour l'Investigation Scientifique des Phénomènes Réputés Paranormaux ("Belgian Committee for Scientific Investigation of Purported Paranormal Phenomena"), is rarely used, except to indicate it inspired the name of the Committee for the Scientific Investigation of Claims of the Paranormal (CSICOP) three decades later.] | 1949 | {{BEL}} | Member of ECSO.[ Serves Wallonia and Brussels.] |
| Czech Skeptics Club Sisyfos / Český klub skeptiků Sisyfos (Sisyfos) | 1995 | {{CZE}} | Member of ECSO. |
| Dakshina Kannada Rationalist Association / தட்சிண கன்னட பகுத்தறிவாளர் ஒன்றியம் (DKRA) | 1976 | {{IND}} | Member of FIRA. |
| The Free Thought / De Vrije Gedachte (DVG) | 1856 | {{NLD}} | Focuses on atheism/secular humanism.["Debunking pseudoscience and other delusions" only became part of the DVG mission statement in 1978.] |
| Edinburgh Skeptics Society (EdSkeptics) | 2009 | {{UK}} | |
| European Council of Skeptical Organisations (ECSO) | 1994 | {{EUR}} | A European umbrella organization, based in Roßdorf, Germany. |
| Federation of Indian Rationalist Associations / இந்திய பகுத்தறிவாளர் ஒன்றியங்களின் பேரவை (FIRA) | 1997 | {{IND}} | Indian umbrella organisation. |
| Freedom From Religion Foundation (FFRF) | 1978 | {{USA}} | Focuses on state/church separation, nontheism, and atheism. |
| French Association for Scientific Information / Association française pour l’information scientifique (AFIS) | 1968[{{cite web |url=http://www.pseudo-sciences.org/spip.php?article23 |title=Notre histoire |author=Jean-Pierre Thomas |work=Website AFIS |publisher=AFIS |accessdate=3 April 2015|language=fr}}] | {{FRA}} | Member of ECSO. |
| German Society for Fighting Quackery / Deutsche Gesellschaft zur Bekämpfung des Kurpfuschertums (DGBK) | 1903 | {{GER}} | Dissolved in 1934. |
| Glasgow Skeptics | 2009 | {{UK}} | |
| Good Thinking Society | 2012 | {{UK}} | |
| Het Denkgelag | 2012 | {{BEL}} | |
| Hungarian Skeptic Society / Szkeptikus Társaság (HSS) | 2006 | {{HUN}} | Member of ECSO. |
| Independent Investigations Group (IIG) | 2000 | {{USA}} | |
| Indian CSICOP | 19?? | {{IND}} | Affiliated with CSI, member of FIRA. |
| Indian Rationalist Association (IRA) | 1949 | {{IND}} | Member of Rationalist International. |
| Irish Skeptics Society | 2002 | {{IRL}} | Member of ECSO. |
| Italian Committee for the Investigation of Claims of the Pseudosciences / Comitato Italiano per il Controllo delle Affermazioni sulle Pseudoscienze (CICAP) | 1989 | {{ITA}} | Member of ECSO. |
| James Randi Educational Foundation (JREF) | 1996 | {{USA}} | |
| Launceston Skeptics | 2010 | {{AUS}} | |
| Maharashtra Committee for Eradication of Blind Faith / Maharashtra Andhashraddha Nirmoolan Samiti (MANS) | 1989 | {{IND}} | Member of FIRA. |
| Merseyside Skeptics Society (MSS) | 2009 | {{UK}} | |
| MTÜ Eesti Skeptik (skeptik.ee) | 2007 | {{EST}} | |
| New England Skeptical Society (NESS) | 1996 | {{USA}} | Fusion of three earlier organisations. |
| New Mexicans for Science and Reason (NMSR) | 1990 | {{USA}} | |
New Zealand Skeptics[The full name is "New Zealand Committee for the Scientific Investigation of Claims of the Paranormal", but this name is rarely used in practice.] (NZ Skeptics) | 1986 | {{NZL}} | |
| Office for Science and Society (OSS) | 1999 | {{CAN}} | McGill University, Montreal. |
| Philippine Atheists and Agnostics Society (PATAS) | 2011 | {{PHL}} | |
Polish Skeptics Club / Klub Sceptyków Polskich (KSP)[{{Cite web |url=http://www.csicop.org/specialarticles/show/the_inception_of_the_polish_sceptics_club |title=The Inception of the Polish Sceptics Club |author=Tomasz Witkowski & Maciej Zatonski |publisher=CSI website |date=18 November 2011 |accessdate=18 July 2014}}][[http://sceptycy.org/ KSP website]] | 2010 | {{POL}} | |
| Portuguese Skeptical Community / Comunidade Céptica Portuguesa (COMCEPT) | 2012 | {{POR}} | |
Rational Alternative to Pseudoscience – Society for the Advancement of Critical Thinking /
Alternativa Racional a las Pseudociencias – Sociedad para el Avance del Pensamiento Crítico (ARP-SAPC) | 1986 | {{ESP}} | Member of ECSO. |
| Rationalist Union / Union Rationaliste | 1930 | {{FR}} | |
| Richard Dawkins Foundation for Reason and Science (RDFRS) | 2006 | {{flag|UK}} & {{flag|US}} | The American and British branches are independent.
|
| Science and Popular Enlightenment / Föreningen Vetenskap och Folkbildning (VoF) | 1982 | {{SWE}} | Member of ECSO. |
| Science and Rationalists' Association of India / Bharatiya Bigyan O Yuktibadi Samiti | 1985 | {{IND}} | Based in Kolkata, West Bengal. |
SKEPP[The letters 'SKEPP' stand for Studiekring voor de Kritische Evaluatie van Pseudowetenschap en het Paranormale ("Study Circle for the Critical Evaluation of Pseudoscience and the Paranormal"), but in practice only the abbreviation is used.] | 1990 | {{BEL}} | Member of ECSO.[ Serves Flanders and Brussels.] |
| Skepsis ry | 1987 | {{FIN}} | Member of ECSO. |
| Skepsis Foundation / Stichting Skepsis (Skepsis) | 1987 | {{NLD}} | Member of ECSO. |
| Skeptical Circle / Círculo Escéptico (CE) | 2006 | {{ESP}} | Member of ECSO. |
Skeptic Society / Общество скептиков[{{Cite episode |url=http://skepticzone.libsyn.com/the-skeptic-zone-283-23march2014 |title=The Skeptic Zone |last=Saunders |first=Richard |authorlink=Richard Saunders (skeptic)|series=The Skeptic Zone |number=283 |format=podcast |publisher=Australian Skeptics |date=23 March 2014 |accessdate=19 July 2014}}] | 2013[{{Cite web |url=https://www.skepticsociety.ru/?s=podcasts_skeptic#041 |title=Выпуск 041 |last=Алфёров |first=Кирилл |work="Скептик" podcast |publisher=Общество скептиков |date=April 2014 |accessdate=1 March 2015}}] | {{RUS}} | |
| Skeptics in the Pub Online | 2020 | {{UK}} / World | |
| Society for the Scientific Investigation of Parasciences / Gesellschaft zur wissenschaftlichen Untersuchung von Parawissenschaften (GWUP) | 1987 | File:German-Language-Flag.svg D-A-CH | Based in Roßdorf, Germany. Member of ECSO. |
| The Skeptics Society | 1992 | {{USA}} | Globally active, but mainly serves California. |
| Young Australian Skeptics (YAS) | 2008 | {{AUS}} | |
| Young Skeptics | 2015 | {{flag|US}} | American after school program. |
