Supply Chain Security Training Act of 2021 This bill requires the Federal Acquisition Institute to develop a training program for officials with supply chain risk management responsibilities at federal agencies (defined to include the legislative and judicial branches, as well as the executive branch, of the federal government). The program shall be designed to prepare such personnel to perform supply chain risk management activities and identify and mitigate supply chain security threats that arise throughout the acquisition life cycle, including for the acquisition of information and communications technology. The Office of Management and Budget shall (1) promulgate guidance to federal agencies requiring executive agency adoption and use of the program, and (2) make the guidance available to federal agencies of the legislative and judicial branches.