Young African Leaders Initiative Act of 2021 or the YALI Act of 2021 This bill provides statutory authority for the Young African Leaders Initiative (YALI), which must seek to build the capacity of young African leaders in sub-Saharan Africa in the areas of business, civic engagement, or public administration. The YALI program must award Mandela Washington Fellowships to young leaders and offer training through regional leadership centers in sub-Saharan Africa to individuals who have demonstrated strong capabilities in entrepreneurship, innovation, public service, and leadership. The Department of State must oversee all U.S.-based activities carried out under the program, and the United States should continue to support overseas initiatives of the program (e.g., access to continued professional training and leadership development opportunities for fellowship alumni upon returning to their home countries). The State Department must also submit an implementation plan for the program and annual reports on the program's progress.