In an effort to counter hate speech, media platforms have increasingly come to rely on ordinary users to fight abusive content. However, little is known about the predictors of this type of user engagement, which we refer to as online civic intervention (OCI). This article presents an experimental inquiry (N = 337) into whether solidarity citizenship norms promote OCI. The results show that users who support solidarity citizenship norms tend to have a greater propensity to flag hate comments and to engage in counterspeech. Overall, this indicates that “good citizens” are more inclined to stand up against hate speech online.