This resource is a research review exploring the relationship between Universal Design for Learning (UDL) and Differentiated Instruction (DI). Abstract: A lot of confusion between UDL and DI exists, especially on how they exactly relate to each other. Consequently, a systematic review was conducted to identify all specific types of interrelationships between both pedagogical models in the literature. In total, 27 peer-reviewed articles were included. Three conceptual interpretations of the UDL and DI interrelationship were identified.