The Kingdom of the Netherlands ]commonly known as the Netherlands,[nb 3] is a sovereign state and constitutional monarchy with the large majority of its territory in Western Europe and with several small West Indian island territories in the Caribbean Sea (in the Leeward Islands and Leeward Antilles groups).

The four parts of the kingdom—the Netherlands, Aruba, Curaçao and Sint Maarten—are constituent countries (landen in Dutch) and participate on a basis of equality as partners in the kingdom. In practice, however, most of the kingdom's affairs are administered by the Netherlands—which comprises roughly 98% of the kingdom's land area and population—on behalf of the entire kingdom. Consequently, Aruba, Curaçao, and Sint Maarten are dependent on the Netherlands for matters like foreign policy and defence, but are autonomous to a certain degree, with their own parliaments.

The vast majority in land area of the constituent country of the Netherlands is in Europe, with the exception of the Caribbean Netherlands: its three special municipalities (Bonaire, Saba, and Sint Eustatius) are located in the Caribbean Sea like the other three constituent countries.