The science of reading (SOR) refers to the sum of what we know about how people learn to read based on empirical studies across multiple disciplines. The purpose of this review was to identify research evidence to inform the SOR for multilingual learners (MLs). We reviewed 30 systematic reviews related to reading and reading instruction for MLs conducted primarily in K-5 U.S. classrooms. Results identified four broad clusters of components related to English reading comprehension as well as instructional practices and programs effective in addressing each component. Clusters included oral language, phonological awareness, decoding and oral reading fluency, and reading comprehension. Notably, oral language and reading skills in both MLs' first language and in English were essential components of the SOR for MLs. Implications for theory and research as well as policy, curriculum, and instruction are provided.