This paper attempts to provide a comprehensive overview of disinformation as a challenge to modern democratic societies. The analysis covers the definitions and evolution of disinformation, as well as its social, psychological, and political impacts. It explores the mechanisms of false narratives and presents concrete case studies – including disinformation related to the energy crisis and the war in Ukraine. The paper also examines the means of counteracting disinformation: from educational initiatives and citizens’ digital competencies, through grassroots fact-checking efforts, to systemic institutional responses in Poland and internationally. The study concludes with recommendations aimed at building information resilience, which today appears to be a crucial condition for the security and sustainability of democracy.