The book offers a collection of essays that reinterpret and reimagine Michael Walzer’s classic work Spheres of Justice as an important contribution to political theorizing about justice in the 2020s. It highlights the social-democratic nature of Walzer’s theory of justice as a significant aid to rethinking egalitarian politics today, as well as some of the deeper structural elements of the theory, such as Walzer’s interpretivism and pluralism. As a result, it both offers the most wide-ranging and up-to-date account of this important book and rethinks some of the major contributions that it has made to political theory and philosophy. Contributors include several senior scholars who are among Walzer’s foremost and most long-standing interlocutors, as well as some of the younger scholars who have done important work in Walzer studies. The volume will stand alongside Palgrave Macmillan’s Walzer and War as a crucial companion to Walzer’s other major book, Just and Unjust Wars.