The purpose of this review is to understand what has been learned over the past 20 years of research on preschool and childcare expulsions in the United States. Our literature search identified 16 research studies on this topic. An extensive review of the identified studies was conducted to critically examine the methods used to measure expulsion, the purposes of the reviewed studies, and interventions used to mitigate expulsion rates. Results from this review revealed that researchers have examined the rates of expulsion and factors that could influence expulsion, such as predictive and risk factors (e.g., demographics, disability status), teachers' roles, teacher--family relationships, and interventions. Notably, the reviewed studies highlighted high rates of expulsion among Black male students and students with disabilities. Many teachers reported high stress, limited access to resources, and challenging relationships with administrators and parents during the process of expulsion. Although a variety of methods (e.g., survey, interview, observation) were used to measure expulsion rates, surveys were the primary method of data collection. Interventions targeting teacher well-being, mental health consultation, and classroom-wide interventions (e.g., Pyramid Model) were found to be promising methods for reducing expulsions. Based on the results, gaps in the literature and implications for future research and practice are discussed.