The current wave of populism has been characterized by visible presence of conspiratorial ideation, i.e., explanations for events that—typically without evidence—assume secretive, malevolent plots involving collective actors. In this chapter, I argue that collective narcissism, i.e., resentment for the lack of recognition of one's own group's entitlement to privileged treatment, lies at the heart of populism. I propose that when people endorse national narcissism, the belief that their national group is exceptional is continually violated by the realization that this exceptionality is not recognized by other groups. This motivates people to search for an explanation for the lack of recognition for their nation that would allow them to maintain its exaggerated image. Conspiracy theories provide external reasons why others question the exceptionality of the nation. They justify constant vigilance to threats to the nation's exceptionality and provide a reassurance that the nation is important enough to attract secretive plots from others. Antagonistic belief in the malicious plotting of others fits the general tendency associated with collective narcissism, to adopt a posture of intergroup hostility. Independently, the aversive arousal stemming from endorsing the collective narcissistic belief motivates people to affirm any available belief and search for any meaningful relations and patterns. This makes them likely to seize on any conspiracy theories because they offer coherent meaning systems often supported by elaborate arguments. Thus, conspiracy theories and conspiratorial thinking satisfy psychological needs associated with collective narcissism.