National Strategy to Ensure American Leadership Act of 2021 or the National SEAL Act of 2021 This bill directs the Department of Commerce to (1) seek to enter into an agreement with the National Academies of Sciences, Engineering, and Medicine to conduct a study to identify the 10 most critical emerging science and technology challenges facing the United States; and (2) develop recommendations for legislative or administrative action to ensure U.S. leadership in matters related to such challenges.