Law is not merely a mechanism of social control but a dynamic instrument through which societies define values, distribute power, and pursue collective welfare. In an era marked by globalization, technological change, environmental crises, and widening social inequality, legal systems are under increasing pressure to adapt while preserving fundamental principles of justice and the rule of law. This review paper critically examines the evolving role of law as a tool of social transformation, emphasizing its influence on governance, access to justice, human rights protection, and sustainable development. Drawing upon classical jurisprudential theory and contemporary empirical scholarship, the paper explores how law responds to social change and how, in turn, it shapes economic growth, environmental stewardship, and democratic accountability. The review highlights persistent challenges such as inequality, regulatory fragmentation, weak enforcement, and digital disruption while proposing strategic reforms for strengthening legal institutions in the twenty-first century. Ultimately, it argues that the legitimacy and efficacy of law in the modern age depend on its capacity to be both a mirror of societal values and a mold for a more just and sustainable future.