Do fact-checks influence individuals' attitudes and evaluations of political candidates and campaign messages? This dissertation examines the influence of fact-checks on citizens' evaluations of political candidates. Using an original content analysis, I determine who conducts fact-checks of candidates for political office, who is being fact-checked, and how fact-checkers rate political candidates' level of truthfulness. Additionally, I employ three experiments to evaluate the impact of fact-checks source and message cues on voters' evaluations of candidates for political office.