Insider trading poses a serious threat to the fairness, transparency, and integrity of securities markets by allowing certain market participants to exploit unpublished price sensitive or material nonpublic information for personal gain. This research paper undertakes a comparative legal analysis of insider trading regulations in India and the United States, examining their conceptual foundations, regulatory frameworks, and enforcement mechanisms. The study analyses the evolution of insider trading law in India under the Securities and Exchange Board of India Act, 1992 and the SEBI (Prohibition of Insider Trading) Regulations, 2015, and contrasts it with the United States regime developed primarily through the Securities Exchange Act of 1934, Rule 10b-5, and judicial doctrines such as the classical theory, tippee liability, and the misappropriation theory. The paper highlights how India follows a predominantly possession based and rule driven regulatory approach, while the United States relies on a fiduciary duty and deception-based model shaped by judicial interpretation. Through an examination of statutory provisions, landmark judicial decisions, and enforcement practices of SEBI and the US Securities and Exchange Commission, the study evaluates the effectiveness of both regimes in protecting investors and maintaining market integrity. The paper concludes by identifying regulatory gaps and best practices and offers reasoned suggestions for strengthening the Indian insider trading framework in light of comparative insights.