The US NRC Radiation Source Regulatory Partnership (RSRP) delivered two virtual training seminars on “Introduction to Regulation of Linear Accelerators in Radiation Oncology” for regulatory staff from Africa and Asia counties on November 5-6, 2020, and from Africa and Former Soviet Union (FSU) countries on November 12-13, 2020. The seminar provided an overview of the LINAC industry standards, physics, machines, beam modification methods, biology of cancer, modern treatment planning, quality assurance/quality management and licensing guidance. Thirty-four (34) regulatory staff from Uganda, Malawi, Mauritius, Iraq, and Afghanistan attended the first seminar. Forty-four (44) regulatory staff from Armenia, Ethiopia, Georgia, Moldova, Mozambique, Rwanda, and Zambia attended the second.