The premise of this special series is that evidence-based interventions and systems change are key foci for building capacity to serve children. In this article, we preface the series by introducing issues relevant to understanding the interplay of these foci and by describing the articles and their contributions. Common elements across these articles include the following: (a) consideration of the importance of evidence-based interventions; (b) data-guided, systematic, formative evaluation within a problem-solving model for localized service delivery and continuous quality improvement; (c) research, policy, and practice alignment; (d) comprehensive, multilayered service delivery informed by public health prevention perspectives; and (e) attention to systems factors related to adoption, adaptation, and sustainability of evidence-based interventions in school contexts. (Contains 1 figure and 1 footnote.)