Recent years have seen an increase in theoretical and empirical interest in the dynamics of social change. Missing from much of this literature, which has focused broadly on collective action, is attention to the people who seek to bring about social change, activists. Mass collective action is unlikely to occur without the involvement of people to recruit, mobilize, and organize social change campaigns. Including recent research from Australia, Europe, and North and South America, and studies of global online activists, this issue highlights multimethod approaches to studying activists and activism across a variety of different regional, issue-based, and sociopolitical contexts. In addition to contributing to ongoing theoretical and empirical discussions, the issue addresses the policy and strategic implications of this research for social change agents and organizations.In December 2011, the U.S. publication Time declared "The Protester" to be the person of the year (Anderson, 2011). Indeed, 2011 was a year of large-scale visible protest and social change around the world: from the Arab Spring; to the "Occupy" (U.S.) and Indignados (Spain) movements; anticorruption protests in India; and protests over accusations of vote rigging in Russia and the Democratic