School‐improvement initiatives are implemented with admirable goals, often requiring substantial human and material resources. However, many fail to be sustainable beyond short‐term funding cycles or the enthusiasm of local initiators. Typically, implementation and improvement are viewed linearly and as static end‐products that fail to consider that schools are complex adaptive systems (CAS) that are continuously and recursively challenged with change. To investigate sustainable school‐improvement within CAS, we used PRISMA‐SR guidelines to conduct a scoping review of peer‐reviewed journal articles extracted from six databases using keywords synonymous with ‘complex or adaptive system’, ‘sustain’, ‘school’ and ‘initiative’. The search process yielded 1146 articles but only 16 of those articles met our inclusion/exclusion criteria that specified that authors present an integrated view of sustainable implementation in schools conceptualised as CAS. Within the selected 16 articles, key components for sustainability in schools described as CAS included access to adequate funding and resources, engagement and involvement of stakeholders, the ability of stakeholders to adapt to change, formation of collaborative partnerships, and the development of supportive policies and procedures. Some important issues arose, such as the tendency of the ‘whole school approach’ to be reduced to information dissemination activities that do not adequately deal with components of complex systems, and the increasing recognition that older implementation models that seek ‘institutionalisation’ fail to appreciate that sustainability is a process, not an end goal. This scoping review highlights the need to recognise the complexity and adaptivity of school systems for successful and sustained implementation of school‐improvement initiatives.