Background: Both medical education and radiation oncology have progressed significantly in the past decade, but a generalized overview of educational research for radiation oncology residents has not been produced. This study examines recent research trends in medical education for residents in radiation oncology through a scoping review. Methods: We conducted a scoping review of medical education research for residents in radiation oncology to survey the research trends. We used publications available on MEDLINE, PubMed, and Scopus to conduct this scoping review. Results: We screened 221 full-text articles, 146 of which met our inclusion criteria. These publications showed increased activity in medical education research for residents, most involving affiliations in the United States. We identified persistent interest in training-, contouring-, and technology-related issues. An increase in research related to career, treatment quality, and multidisciplinary training was also observed. However, no research about teacher training was identified.Conclusions: This scoping review presents the trends in study interests among stakeholders of medical education research in radiation oncology. With an investigation of existing studies, this research identifies areas of high priority and a lack of studies about teacher training. This study provides potential future directions for medical education research for residents in radiation oncology.