Abstract Social media has transformed the way social movements emerge, organize, communicate, and sustain momentum in the modern era. Platform such as Facebook, Twitter (X), Instagram, WhatsApp, and YouTube enable rapid dissemination of information, mobilization of supporters, framing of narratives, and global visibility of local issues. This research paper examines the role of social media in modern social movements, analysing its impact mobilization, participation, leadership structures, and outcomes. It also highlights challenges such as misinformation, digital surveillance, slacktivism, and unequal access. Using theoretical perspectives and contemporary examples, the paper concludes that social media acts as a powerful but double‑edged tool in shaping modern collective action.