This Handbook is a critical resource for carefully considering the possibilities and challenges of strategically integrating participatory action research (PAR) and community development (CD). Utilizing practical examples from diverse contexts across five continents, it looks at how communities are empowering themselves and bringing about systemic change. Chapters provide models for sustainably integrating the two practices and explore the transformative potential of decolonizing innovations and incorporating community organizing. With contributions by leading scholars and practitioners from the global south and north, the Handbook explores ways to build infrastructure to bring PAR and CD together, how to use PAR and CD to build people's power and capacity, and how to integrate PAR and CD in relation to community and organizational capacity building. It further gives practical advice and academic analysis on youth PAR, how to use PAR and CD in crisis situations such as earthquakes and pandemics, and envisions radically alternative PAR and CD approaches. This is a timely resource for social science scholars looking to better understand PAR as an important research method. It rethinks the theories underpinning both PAR and CD, offering important lessons for community development practitioners and non-profit professionals, as well as higher education professors interested in community engagement.