Background: Stepped care is being adopted in many countries as a framework for organizing mental health care in diverse contexts. However, there is a lack of consistency in how it has been defined and operationalized, limiting its effective application in practice. We describe the development of standards for implementing stepped care in Canadian child and youth mental health contexts using a consensus-based approach. These standards are intended to support systems planners in creating more cohesive child and youth mental health systems across Canadian settings. Methods: This study employed learning alliance and Delphi methodologies. A pan-Canadian multi-round Delphi process conducted in English and French was used to derive consensus on the inclusion and wording of individual clauses in the implementation standard. Consensus with a threshold of 70% was set to determine inclusion of individual clauses in the final standard. Results: 68 individuals participated in the Delphi study (with a 76.48% retention rate) representing lived experience, service delivery, policy, and research expertise. Participant feedback indicated a desire for greater specificity, disagreements regarding the concept of shared decision-making, and pragmatic questions about leading systems-wide activities. Over 3 rounds, 29 clause items were revised and reduced to a final list of 24 clause items comprising implementation standards. Discussion: The results of this study represent the first multi-stakeholder, consensus-driven set of standards for implementing stepped care in child and youth mental health settings across Canada. With these standards, we aspire to provide a blueprint for advocacy and reform toward stronger, more coordinated mental health systems.