conspiracy theorist

• (Received Pronunciation) IPA^(key): /kənˈspɪɹ.ə.si ˌθɪəɹɪst/
• (General American) IPA^(key): /kənˈspɪɹ.ə.si ˌθi.ɚ.əst/, /- ˌθɪɚ.əst/, /- ˌθɪɚ.ɪst/
• (General Australian) IPA^(key): /kənˈspɪɹ.ə.siː ˌθɪə.ɹəst/, /- ˌθiː.ə.ɹəst/
• (New Zealand) IPA^(key): /kɘnˈspɘɹ.ɘ.siː ˌθiə.ɹɘst/, /- ˌθiː.ɘ.ɹɘst/

conspiracy theorist (plural conspiracy theorists)

1. (chiefly derogatory) One who believes in, follows, or advances a conspiracy theory.

   Mike's a conspiracy theorist; he thinks NASA faked the moon landings.

   • 1993, Christopher Hitchens, For the Sake of Argument:

     And you may have noticed that those who are too quick to shout 'conspiracy theorist' are equally swift, when consequences for authority and consensus impend, to look serious and say 'It's more complicated than that.' These have become standard damage-control reflexes.

   • 2024 April 19, Aaron Pellish, “RFK Jr.’s onetime allies in environmental advocacy call for him to drop out”, in CNN‎^[1]:

     “Robert F. Kennedy, Jr. is not an environmentalist. He is a dangerous conspiracy theorist and science denier whose agenda would be a disaster for our communities and the planet,” the letter reads.

   • 2025 July 16, Ryan Bort and Asawin Suebsaeng, “Trump calls Epstein conspiracy a ‘hoax’ and turns on Maga ‘weaklings’”, in Rolling Stone‎^[2]:

     Rep. Marjorie Taylor Greene (R-Ga.), one of the most notorious conspiracy theorists and MAGA diehards in Congress, told The New York Times that the DOJ’s memo is “a full reversal on what was all said beforehand, and people are just not willing to accept it.”

• conspiratard (slang, derogatory), conspiracist, conspirophile (rare)
• tinfoil hatter (slang, derogatory), truther
• conspiracy analyst (nonpejorative)

• (US) crackpot (slang)
• (UK) crank (slang)