--- - |2 This paper serves as an Introduction by the co‐editors to a Special Section of Child Development entitled “Meta‐analysis and Individual Participant Data Synthesis in Child Development.” First, the co‐editors emphasize that the work contained in the Special Section was selected to highlight the value of meta‐analysis not only for synthesizing study‐level published and unpublished data but also as regards its ability to support programmatic, replicable, and cumulative developmental science. Second, the co‐editors identify some of the cross‐cutting themes of the papers featured in the Special Section, including the value of meta‐analysis for summarizing and interrogating the full range of developmental science and in potentially transforming conventional wisdom in given domains along with the importance of recent innovations for improving standard meta‐analytic practice–particularly in the context of developmental questions. Emphasized especially are contributions to the Special Section that extend classic meta‐analysis to individual participant data synthesis. - Child Development, EarlyView.