The success of non-pharmaceutical interventions to contain pandemics often depends greatly upon voluntary compliance with government guidelines. What explains variation in voluntary compliance? Using mobile phone and survey data, we show that during the early phases of COVID-19, voluntary social distancing was higher when individuals exhibit a higher sense of civic duty. This is true for U.S. individuals, U.S. counties, and European regions. We also show that after U.S. states began re-opening, social distancing remained more prevalent in high civic capital counties. Our evidence points to the importance of civic capital in designing public policy responses to pandemics.