Democracies around the world face rising levels of disinformation. The intentional spread of falsehoods and related attacks on the rights of minorities, press freedoms, and the rule of law all challenge the basic norms and values on which institutional legitimacy and political stability depend. The many varieties of disinformation include: politicians lying about their policies and political activities, attacks on the scientific evidence surrounding important issues such as climate change, the spread of “deep state,” “globalist” and various historically unsavory conspiracy theories, and the invention of stories to inflame existing social and political conflicts. The sources of these claims include elected politicians, movement leaders, social media influencers, foreign governments, and political information sites that often use familiar journalistic formats to package propaganda. Most of these efforts come from the radical right movements, parties and wealthy libertarian interests that oppose broad and inclusive democratic representation and the public interest protections of government. While this chapter focuses primarily on the United States, similar patterns can be found in many other democratic nations.