Global challenges such as climate change demand transnational responses, including from legal clinics. Building on earlier community legal clinic and international human rights clinic models, transnational legal clinics combine the objectives of legal clinics with the framework of transnational law to work across domestic and international planes. This article focuses on a Canadian–Peruvian legal clinic collaboration to research and draft an amicus curiae brief for landmark climate litigation in Peru. While the global north–south axis of collaboration raises structural challenges, adopting a transnational approach unites participants around the principle of solidarity and decentres assumptions about expertise. A transnational approach also contributes to the progressive development of law, in this case by offering insights into remedies in climate litigation. Overall, we argue that transnational legal clinic collaboration can spur participants’ reflective learning and make substantive contributions to the growing number of climate cases.