The purpose of this study was to assess the feasibility and implementation of a text message intervention to teach adolescents bystander intervention strategies. Adolescents (N = 123) engaged daily for 15 days with bystander education materials and questions sent to them by text message to their personal cell phones. The likelihood to intervene on social media increased over the course of the intervention, but the same was not found for likelihood to intervene in person. The likelihood to intervene in the individual bystander intervention scenarios presented were however significant predictors of likelihood to intervene on social media and in person. This study provides promising preliminary evidence that delivering bystander intervention education to adolescents via their cell phones has the potential to teach them how to recognize and respond as a bystander to bullying and harassment among their peers, especially in online spaces such as social media.