Socially withdrawn children frequently refrain from social activities in the presence of peers. The lack of social interaction in childhood may result from a variety of causes, including social fear and anxiety or a preference for solitude. From early childhood through to adolescence, socially withdrawn children are concurrently and predictively at risk for a wide range of negative adjustment outcomes, including socio-emotional difficulties (e.g., anxiety, low self-esteem, depressive symptoms, and internalizing problems), peer difficulties (e.g., rejection, victimization, poor friendship quality), and school difficulties (e.g., poor-quality teacher-child relationships, academic difficulties, school avoidance). The goals of the current review are to (a) provide some definitional, theoretical, and methodological clarity to the complex array of terms and constructs previously employed in the study of social withdrawal; (b) examine the predictors, correlates, and consequences of child and early-adolescent social withdrawal; and (c) present a developmental framework describing pathways to and from social withdrawal in childhood.