Fostering Overseas Rule of law and Environmentally Sound Trade Act of 2021 or the FOREST Act of 2021 This bill restricts certain commodities produced on illegally deforested land from accessing the U.S. market. Specifically, the bill prohibits the importation of any product made wholly or in part of a covered commodity produced from illegally deforested land. The bill outlines requirements for import declarations of covered commodities. The U.S. Trade Representative (USTR) must, within 30 days, publish (1) an initial list of covered commodities that consists of palm oil, soybeans, cocoa, cattle, rubber, and wood pulp; and (2) an initial list of covered products that are defined by the bill in accordance with the Harmonized Tariff Schedule. These lists must be updated at least on an annual basis. Further, the USTR must identify foreign countries without adequate and effective protection against illegal deforestation caused by the production of commodities that are likely to enter the United States. The USTR must develop an action plan that includes benchmarks for each identified country. Additionally, the bill creates an interagency working group to provide advice and recommendations to the USTR, U.S. Customs and Border Protection, and other relevant agencies. The bill provides funding to assist foreign governments in combating illegal deforestation. The bill also includes illegal deforestation as a specified unlawful activity under a federal financial crime statute. The bill establishes a federal procurement preference for commodities that are not produced from land subject to deforestation.