Despite a growing literature on the topic, little is known about how individuals perceive the label “conspiracy theory”. In two studies, we compare social representations of conspiracy theories, and how these are influenced by individuals’ own conspiracy beliefs. In addition, we examine how these representations relate to how scholars define and explain conspiracy theories. In Study 1, we used lexicometric analysis to explore the vocabulary that French participants (n = 939) spontaneously associated with the notion of ‘conspiracy theory’ and the personal definitions they provided. The representation of participants scoring high on the generic conspiracist beliefs scale was centred on the content of conspiracy theories (e.g., “lies” or “government”). By contrast, the representation of participants scoring low on the conspiracist beliefs scale was centred on the believer (e.g., “paranoia” or “cognitive biases”). They proposed definitions of conspiracy theories centred on the function(s) conspiracy theories supposedly fulfil for the believer (e.g., simplify complex realities). To make sure that these results did not merely express participants’ endorsement or rejection of conspiracy theories, we carried out a second study. In Study 2 (n = 272), we found that the more participants endorsed generic conspiracist beliefs, the less they mobilised intra-individual causes (e.g., reasoning biases) to explain why some people believe in conspiracy theories that they did not endorse themselves. This research shows that people’s representations of conspiracy theories differ depending on their conspiracy beliefs.