The death of a loved one represents one of the most distressing and potentially traumatic life events in childhood and adolescence. Grief reactions in youth are influenced by ongoing developmental processes and manifest differently depending on the child’s age and developmental stage. These grief-related processes unfold within youths’ caregiving context, as children and adolescents rely heavily on the adults in their environment to navigate and cope with the death of a loved one. Despite the field’s increasing recognition of the potential for maladaptive grief reactions to impede functioning over time, few longitudinal research studies on childhood grief currently exist. In this article, we will (a) provide a brief overview of the childhood bereavement literature; (b) review the new DSM-5 and ICD-11 Prolonged Grief Disorder diagnostic criteria through a developmentally-informed lens; (c) describe how grief reactions manifest in children and adolescents of different ages through the lenses of multidimensional grief theory and relational developmental systems theory; (d) highlight key moderating factors that may influence grief in youth, and (e) discuss a primary moderating factor, the caregiving environment, and the potential mechanisms through which caregivers influence children’s grief.