Civics Learning Act of 2021 This bill expands the use of American History and Civics Education—National Activities grants to prioritize innovative civics learning and teaching. Specifically, the bill expands the allowable uses of these grants to include before-, during-, and after-school activities and extracurricular activities; activities that include service learning and community service projects that are linked to school curriculum; activities that encourage and support student participation in school governance; and online and video game-based learning. Further, the Department of Education must ensure that specified percentages of grant funds are awarded on a diverse basis to eligible entities (e.g., institutions of higher education) that serve students and teachers at elementary schools, middle schools, and high schools.