Protect Our Workers Act of 2021 This bill requires the Army Corps of Engineers to provide to each Corps district clarifying, uniform guidance with respect to prevailing wage requirements for its contractors and subcontractors. This guidance must conform with the Department of Labor's regulations, policies, and guidance with respect to the proper implementation and enforcement of the Davis-Bacon Act and other related acts; direct Corps districts to investigate worker complaints and third-party complaints within 30 days of the date of filing; and instruct Corps districts that certified payroll reports submitted by contractors and subcontractors and the information contained therein shall be publicly available and are not exempt from disclosure under the Freedom of Information Act.