Welcoming over 700 delegates across the two-day event, the 2021 Tolkien Society summer seminar was the highest attended event in the Society's history. It invited scholars to consider the role that diversity plays in Middle-earth's linguistic and literary make-up: how does he explore race, gender, sexuality, disability, class, religion and faith, and age? How do different fandoms receive his works? How can varying perspectives enrich our understanding of Arda? Tolkien and Diversity was the second of three seminars that the Tolkien Society hosted online in 2021, reaching over 1600 global delegates. Published under the auspices of the Society's Peter Roe Memorial Fund, this proceedings features a collection of papers delivered at the Tolkien Society 2021 summer seminar.