This research paper examines the transformative role of judicial activism in expanding the scope of environmental rights under Article 21 of the Indian Constitution, which guarantees the right to life and personal liberty. Though the Constitution does not explicitly recognize the right to a healthy environment as a fundamental right, the Indian judiciary has interpreted Article 21 progressively to include environmental protection as intrinsic to the right to life. Through landmark judgments, such as M.C. Mehta v. Union of India, Subhash Kumar v. State of Bihar, and T.N. Godavarman v. Union of India, courts have laid the groundwork for a rights-based environmental jurisprudence that incorporates international legal principles like sustainable development, the precautionary principle, and the public trust doctrine. The paper explores the philosophical and legal basis of environmental rights, traces their evolution through judicial precedents, analyzes the dynamic role of the judiciary in environmental governance, and identifies the challenges in implementation. It also contextualizes the Indian experience in the global discourse on ecological constitutionalism and highlights its relevance for countries seeking to integrate environmental protection with human rights. Finally, it offers recommendations for institutional reform, legal clarity, and public participation to ensure that environmental rights move from being judicially declared to practically realized.