This is a list of sovereign states by constitutionally-defined de jure system of government. This list does not measure the degree of democracy, political corruption, or state capacity of governments. See more

Semi-presidential republics
In a semi-presidential republic a president exists alongside a prime minister and a cabinet, with the latter two being responsible to the legislature. It differs from a parliamentary system in that it has an executive … See more

Specifically, monarchies in which the monarch's exercise of power is unconstrained by any substantive constitutional law. The monarch acts as both head of state … See more

The exact political character of the European Union is debated, some arguing that it is sui generis (unique), but others arguing that it has features of a federation or a confederation. It has elements of intergovernmentalism, with the European Council See more

Constitutional monarchies
These are systems in which the head of state is a constitutional monarch; the existence of their … See more

• Iran combines the forms of a presidential republic, with a president elected by universal suffrage, and a theocracy, with a Supreme Leader who is ultimately responsible for state … See more

Unitary states
A state governed as a single power in which the central government is ultimately supreme and any administrative divisions (sub-national units) exercise only the powers that the central government chooses to … See more