Girls' Leadership, Engagement, Agency, and Development Act of 2021 or the Girls LEAD Act This bill directs the Department of State and the U.S. Agency for International Development (USAID) to jointly report to Congress a strategy to strengthen the participation of adolescents, particularly girls, in democracy, human rights, and governance. The State Department and the USAID shall (1) implement activities to achieve this goal, including activities to increase adolescent girls' civic and political knowledge and skills and address barriers to political participation; and (2) prioritize foreign assistance funding for democracy, human rights, and governance programs toward achieving the goals in this bill.