ABSTRACT The 2022 ‘Women, Life, Freedom’ protests in Iran have led to the escalation of state-sponsored online disinformation campaigns. This paper aims to examine how, amidst a growing legitimacy crisis, the Iranian regime has employed a ‘Big Lie’ to shatter hopes for change by discrediting influential dissidents and hindering the formation of an effective opposition movement. Three target groups have borne the brunt of this strategy: celebrities, political dissidents inside the country, and prominent opponents in the diaspora. By reviewing state-owned media content and tweets, this paper reveals a consistent pattern of character assassination against dissidents. The ruling regime’s ultimate goal is to foster a sense of public hopelessness for an alternative to the Islamic Republic. By conceptualizing the Big Lie online, the study engages with the mechanism of control in modern despotism in the age of the internet and social media.