Does the use of right-wing social media translate into right-wing protest and violence? Recent research linking social media activity to political attitudes, participation in large, isolated demonstrations, and the occurrence of hate crimes suggests a relationship between right-wing social media activity and subsequent contentious events and violence. However, analyzing this relationship at countrywide scales over many months has not been possible in the absence of reliable georeferenced social media and corresponding contentious politics data. We create a spatial panel dataset measuring 57,505 right-wing social media posts and 1,765 incidents of right-wing unrest in all United States counties from January 2020 through January 2021. Using spatial regression analysis, we find that right-wing social media activity in a given month increased the frequency of right-wing unrest events in the following month. A content analysis of 1.5 million Parler comments reveals that discussions of political events were relatively rare, suggesting that while right-wing social media can be used to coordinate political unrest, this may not fully explain the positive relationship between online and offline activity. Instead, a subsequent analysis of politically moderate and conservative counties indicates that the main effect we observe is driven by shifting perceptions of norms and not changes in individuals’ beliefs or preferences. Our results help explain how social media affect political unrest beyond the conventional coordination mechanism and inform an emerging literature on social media, political attitudes and action, and violence.