A Minister of State, in parliamentary systems, is a junior minister. They may be listed as a member of cabinet, or they may not be considered part of the cabinet, instead being assigned to assist a specific cabinet minister.

In the United Kingdom, a Minister of State is junior to a Secretary of State but senior to a normal Minister. Ministers of State are responsible to their Secretaries of State.

Somewhat paradoxically, in Canada, a Minister of State is senior to a Secretary of State but junior to a Minister of the Crown, or normal minister. See Minister of State (Canada).

In the Republic of Ireland, a Minister of State is junior to a Minister of a Department of State or normal minister and of similar standing to the previous Parliamentary Secretary. See Minister of State (Ireland).

In the Netherlands, Minister of State is a title of honour, declared by Queen Beatrix of the Netherlands. It is given in exceptional cases to politicians. A Minister of State advises the queen in certain situations, and can also be asked for advice by others on constitutional issues. This is also true in Belgium.