This article considers how domestic protests influence coups. Protests signal regime illegitimacy, which incentivizes coups and provides a favorable climate for postcoup reforms. Protests also ease coordination obstacles among coup plotters and make international actors less likely to punish coup leaders. We expect these signaling processes to be strongest when protests take place near the capital or are nonviolent. Our empirical analyses introduce event-level protest data from the Social, Political, and Economic Event Database project into the coup literature. Examining a global sample of coup attempts from 1951 to 2005, we find strong support for our theoretical expectations. Our discussion provides implications for scholars studying coups and nonviolent movements more generally. It also speaks to the influence of external actors on social uprisings and highlights the importance of geographical disaggregation in the study of dissident behavior.