Advances in social norm research indicated the potential benefit of utilizing social referents, who are highly connected to others and have outstanding positions in social networks, and therefore may effectively provide normative cues for other group members. Addressing the need to increase intergroup tolerance among adolescents, we developed an intervention for secondary schools focusing on network-identified social referents, who were encouraged to spread "Equality-Based Respect" norms to increase peer-to-peer tolerant relationships. We examined the feasibility, acceptability, and effectiveness of "Together for Tolerance" in a waitlist-controlled trial (N= 1,339). Implementation was largely as planned, with high acceptability among randomly selected social referents. However, we observed no increase in perceived respect norms or tolerant behaviors, apart from a potential short-term benefit in tolerance among students exposed to peer-led actions. We address conceptual (e.g., the role of norms) and methodological (e.g., positive initial attitudes) limitations, and suggestions for future implementation and evaluation.