Big data holds immense potential for innovation and new understanding in research, evaluation, practice, and policy related to young children and their families. Although big data is a relatively new concept, particularly in early intervention systems (EI), recent pushes for data systems alignment in EI and education have propelled the use of large-scale integrated data systems in recent years (U.S. Department of Health and Human Services & the U.S. Department of Education, 2016). This combined with a plethora of new and rapidly increasing data sources has created a new data world. In response, research methodology, ethics, and tools need to be examined to ensure developmentally appropriate and ethical practices in research. A mixed methods systematic scoping review was conducted to gain a foundational understanding of the literature on big data use in EI settings. Strengths, challenges, systems-level needs, and implications for researchers, administrators, and policy makers are included.