The Doctrine of Promissory Estoppel: A Public Law Perspective is the first dedicated public law treatise on one of Indian jurisprudence's most litigated yet least systematically examined doctrines. The work positions it as a mature principle of administrative and constitutional accountability—one that has been shaped, tested, and refined through landmark Supreme Court rulings from Indo-Afghan Agencies to Motilal Padampat, and applied across taxation, land reform, governmental incentives, and political promises. Across ten rigorously structured chapters, the book traces the doctrine's intellectual lineage from English equity, analyses its key limitations, and offers a nuanced comparative treatment of promissory estoppel and legitimate expectation that clarifies where each doctrine provides a stronger remedy against the State. The final chapter raises pointed questions about judicial inconsistency, doctrinal conflation, and the pressing need for certainty in Indian public law.