The doctrine of legitimate expectation operates in the domain of administrative law. It provides that where a public authority has made a representation — whether by a promise, a past practice, or a published policy — upon which a person has relied, the authority cannot frustrate that expectation without providing the person a fair hearing and, where appropriate, a good reason for the departure. The doctrine is a creature of procedural fairness: it does not guarantee the substantive outcome the person expected, but it guarantees a process before that expectation is defeated.
In Indian law, the doctrine was recognised by the Supreme Court in cases such as Union of India v. Hindustan Development Corporation (1993) and has been applied in employment, licensing, and regulatory contexts. The doctrine cannot be invoked to enforce a representation that is contrary to law or one that the authority had no power to make. Nor can it be used to compel the government to exercise a statutory power in a particular way contrary to the public interest.