Dominica has a Westminster parliamentary system of government. Under the Constitution adopted at independence on 3 November 1978 politics in Dominica takes place in a framework of a parliamentary representative democratic republic, whereby the Prime Minister of Dominica is the head of government, and of a multi-party system. Executive power is exercised by the government. Legislative power is vested in both the government and the House of Assembly. The Judiciary is independent of the executive and the legislature.

Executive branch

A President and Prime Minister make up the executive branch. Nominated by the Prime Minister in consultation with the Leader of the Opposition party, the President is elected for a 5-year term by the parliament. The President appoints as Prime Minister the person who command the majority of elected representatives in the parliament and also appoints, on the Prime Minister's recommendation, members of the parliament as cabinet ministers. The Prime Minister and cabinet are responsible to the parliament and can be removed on a no-confidence vote.

Legislative branch

The unicameral parliament, the House of Assembly, has 32 members.  Twenty one (21) members are elected for a five-year term in single-seat constituencies in a "first-past-the-post" plurality system.  Nine members are senators appointed by the President – five on the advice of the Prime Minister, and four on the advice of the Leader of the Opposition. In addition there is a Speaker elected from among persons who are not members of the House, responsible for the management and general administration of the House, and one ex-officio Clerk of the House. The head of state - the President - is elected by the House of Assembly. The regional representatives decide whether senators are to be elected or appointed. If appointed, five are chosen by the President with the advice of the Prime Minister and four with the advice of the opposition leader. If elected, it is by vote of the regional representatives.

Elections for representatives and senators must be held at least every 5 years, although the Prime Minister can call elections any time. Dominica has a two-party system, which means that there are two dominant political parties, with extreme difficulty for anybody to achieve electoral success under the banner of any other party. Dominica was once a three-party system, but in the past few years the Dominica Labour Party and the greatly diminished Dominica Freedom Party have built a coalition.

Judicial branch

The judiciary exercises its authority independently of both the executive and legislative branches.  Dominica's legal system is based on English common law.

Dominica has a multi-level judicial system commencing with the Lower Court, or Magistrate's Court, which is the first level of recourse for violators of the country's laws. The government-employed magistrate makes decisions at this level without the benefit of a jury. At the next level, a judge, assisted by a jury, presides over civil and criminal cases. Jurors are selected from the list of registered voters and, unless excused by the court, are obliged to serve when called. Appeals may be made to the Eastern Caribbean States Supreme Court, headquartered in Saint Lucia, which consists of a Court of Appeal and a High Court. A panel of judges is appointed to hear appeals, and these sittings take place on the island. The court of last resort for Dominicans is the Judicial Committee of the Privy Council in London, where decisions of the Supreme Court may be reviewed for final ruling.

Local Government

Local government is provided for by the Town Council Act 1937, the Village Council Act 1954, the Carib Council Act 1978, the City Council Act 1984 and the Urban Council Act 1992, and not by the constitution. For the purpose of local government there are three urban councils, 37 village councils and the Carib Council in the Kalinago (Carib) territory. The local authorities have powers to raise revenue from property and land taxes, and they receive transfers from national government, which include amounts matching revenues collected by authorities. The largest part of local government spending is on road maintenance.