Gene Sharp’s The Politics of Nonviolent Action provides a comprehensive account of non-violent strategies and tactical actions adopted by social movements globally. Sharp not only articulates the basis of political power that is challenged by movement activists, but indicates the relative advantages of tactical non-violence over violence when seeking societal change. This paper considers the legacy of Sharp’s seminal book and appraises its continuing theoretical and empirical relevance for the study of social movements. The strategic underpinning of Sharp’s non-violence theory is shown to be complemented by non-material factors, such as emotions and ideological belief, that motivate activism against sources of authority. This paper also shows that Sharp’s advocacy of non-violent action is affirmed by recent empirical literature that shows that non-violence is more effective in helping to achieve movement goals. Theoretical and empirical developments following the publication of The Politics of Nonviolent Action have vindicated Sharp’s original insights.