Kinesiology is a field focused on physical activity and its impact on health, society, and quality of life. But do all people have equal opportunities to access and experience physical activity? Do physical activity settings allow people to freely express themselves? Are the benefits of physical activity universally shared by all people? If the answer to any of these questions is “no,” then these questions demand not only our immediate attention, but also our collective action. During the National Academy of Kinesiology’s 90th anniversary meeting, September 22–24, 2021, these questions and others were explored through presentations devoted to the theme “Kinesiology’s Social Justice Imperative.” This essay overviews the meeting, its purpose, and the organizers and introduces the 11 thematic papers in the “Proceedings of the National Academy of Kinesiology’s 2021 Meeting: Kinesiology’s Social Justice Imperative” issue, plus a 12th essay commemorating the National Academy of Kinesiology’s 90th anniversary meeting.