List of countries by system of government

A colour-coded legend of forms of government.

Legend

•   Presidential republic: Head of state is a president that is the head of government and is independent of legislature
•   Semi-presidential republic: Head of state is a president that has some executive powers and is independent of legislature; remaining executive power is vested in ministry that is subject to parliamentary confidence
•   Republic with an executive presidency or directory nominated by or elected by the legislature: President or Directory is both head of state and government; ministry, including the president, may or may not be subject to parliamentary confidence
•   Parliamentary republic: Head of state is a president that is mostly or entirely ceremonial; ministry is subject to parliamentary confidence
•   Constitutional monarchy (ceremonial): Head of state is a monarch that is mostly or entirely ceremonial; ministry is subject to parliamentary confidence
•   Constitutional monarchy (executive): Head of state is an executive monarch; monarch personally exercises power in concert with other institutions; sometimes known as a semi-constitutional monarchy
•   Absolute monarchy: Head of state is executive; all authority vested in absolute monarch
•   One-party state: Head of state is executive or ceremonial; power constitutionally linked to a single political party
•   Countries in which constitutional provisions for government have been suspended (e.g. military juntas)
•   No constitutionally defined basis to current regime (e.g. transitional governments)
•   Overseas possessions, colonies, and places without governments

Note: this chart represent de jure systems of government, not the de facto degree of democracy. Several states that are constitutional republics are in practice ruled as authoritarian states.

These are systems in which a president is the active head of the executive branch of government, and is elected and remains in office independently of the legislature.

In full presidential systems, the president is both head of state and head of government. There is generally no prime minister, although if one exists, in most cases they serve purely at the discretion of the president.

The following list includes democratic and non-democratic states:

Nations with limited recognition are in italics.

•  Iran[note 5]

The following countries have presidential systems where a post of prime minister (official title may vary) exists alongside that of the president. The president is still both the head of state and government and the prime minister's roles are mostly to assist the president.

Nations with limited recognition are in italics.

In semi-presidential systems, there is always both a president and a head of government, commonly but not exclusively styled as a prime minister. In such systems, the president has genuine executive authority, but the role of a head of government may be exercised by the prime minister.

The president chooses a prime minister and cabinet from the parliament with approval from the parliament, however only the parliament may remove them from office with a vote of no confidence. The president does not have the right to dismiss the prime minister or the cabinet.

Nations with limited recognition are in italics.

The president is head of state and the prime minister is head of government, although the prime minister generally works under the discretion of the former more so than in a premier-presidential system. The president chooses the prime minister and the cabinet without a confidence vote from the parliament, but must have the support of a parliamentary majority for their selection. In order to remove a prime minister or their cabinet from power, the president may dismiss them or the parliament can remove them by a vote of no confidence.

Nations with limited recognition are in italics.

In a parliamentary republic, the head of government is selected or nominated by the legislature and is also accountable to it. The head of state is ordinarily called a president and (in full parliamentary republics) is separate from the head of government, serving a largely apolitical, ceremonial role. In these systems, the head of government is usually called the prime minister, chancellor or premier. In mixed republican systems and directorial republican systems, the head of government also serves as head of state and is usually titled president.

In some full parliamentary systems, the head of state is directly elected by voters. Under other classification systems, however, these systems may instead be classed as semi-presidential systems (despite their weak presidency).[11] Full parliamentary republican systems that do not have a directly elected head of state usually use either an electoral college or a vote in the legislature to appoint the president.

Nations with limited recognition are in italics.

A combined head of state and head of government in the form of an executive president is either elected by the legislature or by voters after candidates are nominated for the post by the legislature (in the case of Kiribati), and they must maintain the confidence of the legislature to remain in office. In effect, "presidents" in this system function the same as prime ministers do in other parliamentary systems.

A combined head of state and head of government (usually titled president) is elected by the legislature but is immune from a vote of no confidence (as is their cabinet), thus acting more independently from the legislature.[29] They may or may not also hold a seat in the legislature.

In a directorial republic, a council jointly exercises the powers and ceremonial roles of both the head of state and head of government. The council is elected by the parliament, but it is not subject to parliamentary confidence during its fixed term.

These are systems in which the head of state is a constitutional monarch; the existence of their office and their ability to exercise their authority is established and restrained by constitutional law.

Systems in which a prime minister is the active head of the executive branch of government. In some cases, the prime minister is also leader of the legislature, while in other cases the executive branch is clearly separated from legislature (although the entire cabinet or individual ministers must step down in the case of a vote of no confidence).[31][32] The head of state is a constitutional monarch who normally only exercises his or her powers with the consent of the government, the people and/or their representatives (except in emergencies, e.g. a constitutional crisis or a political deadlock).[note 14]

The prime minister is the nation's active executive, but the monarch still has considerable political powers that can be used at their own discretion.

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 and head of government.

States in which political power is by law concentrated within one political party whose operations are largely fused with the government hierarchy (in contrast to states where a multi-party system formally exists, but this fusion is achieved anyway through election fraud or underdeveloped multi-party traditions).

Nations with limited recognition are in italics.

A committee of the nation's military leaders controls the government for the duration of a state of emergency. Constitutional provisions for government are suspended in these states; constitutional forms of government are stated in parentheses.

States that have a system of government that is in transition or turmoil. These regimes lack a constitutional basis.

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 delegate. The majority of states in the world have a unitary system of government. Of the 193 UN member states, 126 are governed as centralized unitary states, and an additional 40 are regionalized unitary states.

States in which most power is exercised by the central government. What local authorities do exist have few powers.

States in which the central government has delegated some of its powers to regional authorities, but where constitutional authority ultimately remains entirely at a national level.

States in which the national government shares power with regional governments with which it has legal or constitutional parity. The central government may or may not be (in theory) a creation of the regional governments.