A protectorate, in the context of international relations, is a state that is under protection by another state for defence against aggression and other violations of law. It is a dependent territory that enjoys autonomy over most of its internal affairs, while still recognizing the suzerainty of a more powerful sovereign state without being a possession. In exchange, the protectorate usually accepts specified obligations depending on the terms of their arrangement. Usually protectorates are established de jure by a treaty. Under certain conditions—as with Egypt under British rule (1882–1914)—a state can also be labelled as a de facto protectorate or a veiled protectorate.

A protectorate is different from a colony as it has local rulers, is not directly possessed, and rarely experiences colonization by the suzerain state. A state that is under the protection of another state while retaining its "international personality" is called a "protected state", not a protectorate.