Tiered frameworks, such as Response to Intervention (RtI), have become a primary approach within K-12 settings for identifying children who may need additional intervention. Recent literature suggests RtI is also occurring in many early childhood programs, and early literacy is often an area of focus. While there are data indicating improved outcomes for children who received early literacy intervention, we had many unanswered questions regarding the characteristics of early literacy interventions implemented with young children within RtI frameworks. Using Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines, we conducted a systematic review of the literature to understand "who" the studies were about, "how" the researchers identified children in need of higher tiers of support, "what" content was emphasized through "which" intervention methods, and "where" and "when" the interventions occurred. Our findings indicate that intervention studies overwhelmingly occurred with young children from racially and ethnically minoritized communities and economically marginalized backgrounds. Interventions focused on early literacy skill areas related to later reading achievement and were often delivered by members of research teams. We discuss implications for practitioners striving to implement research-based interventions in their classrooms. We also discuss implications for researchers seeking to design and implement early literacy intervention studies with practical applicability.