The purpose of this paper is to describe the integration of tiered interventions and supports in secondary schools, sometimes referred to as multi-tiered systems of support (MTSS). The interventions include academic, behavioural, social, and emotional supports for all students.A description of the connections across specific MTSS systems, datasets, and practices is discussed. The article addresses the implementation of MTSS through the lens of school improvement and implementation science. A case example of a school implementing MTSS is provided to highlight the strengths and challenges of MTSS in secondary settings.School Improvement, Implementation, and MTSS 3 The purpose of this paper is to describe the integration of tiered intervention supports in secondary school settings. Schools place an emphasis on academic, behavioural, emotional, and social supports, the goal being to prevent failure for students at risk. The interventions include data-driven, evidence-based solutions for struggling students. However, these approaches are not always aligned. Schools are making efforts to provide a cohesive framework for intervention in schools through multi-tiered systems of support (MTSS). In this paper we provide a discussion of the assimilation of support systems through school improvement and implementation science. It also provides a case example of this integration at the secondary school level.