BACKGROUND: The coronavirus disease 2019 (COVID-19) pandemic has greatly affected medical education in addition to clinical systems. Residency training has probably been the most affected aspect of medical education during the pandemic, and research on this topic is crucial for educators and clinical teachers. The aim of this study was to understand the effect of the COVID-19 pandemic comprehensively through a systematic review and analysis of related published articles. METHODS: A systematic review was conducted based on a predesigned protocol. We searched MEDLINE and EMBASE databases until November 30, 2020, for eligible articles. Two independent reviewers extracted data by using a customized form to record crucial information, and any conflicts between the two reviewers were resolved through discussion with another independent reviewer. The aggregated data were summarized and analyzed. RESULTS: In total, 53 original articles that investigated the effect of the COVID-19 pandemic on residency training were included. Studies from various regions were included in the research, with the largest percentage from the United States (n = 25, 47.2%). Most of these original articles were questionnaire-based studies (n = 44, 83%), and the research target groups included residents (79.55%), program directors (13.64%), or both (6.82%). The majority of the articles (n = 37, 84.0%) were published in countries severely affected by the pandemic. Surgery (n = 36, 67.92%) was the most commonly studied field. CONCLUSIONS: The COVID-19 pandemic has greatly affected residency training globally, particularly surgical and interventional medical fields. Decreased clinical experience, reduced case volume, and disrupted education activities are major concerns. Further studies should be conducted with a focus on the learning outcomes of residency training during the pandemic and the effectiveness of assisted teaching methods.