All executive authority is vested in the monarch, and royal assent is required for the Parliament of Saint Vincent and the Grenadines to enact laws and for letters patent and Orders in Council to have legal effect.

Most of the powers are exercised by the elected members of parliament, the ministers of the Crown generally drawn from amongst them, and the judges and justices of the peace.

A representative assembly was authorised in 1776, Crown Colony government was installed in 1877, a legislative council was created in 1925 with a limited franchise, and universal adult suffrage was granted in 1951.

[2] Saint Vincent was granted "associate statehood" status by Britain on 27 October 1969, giving it complete control over its internal affairs.

[5] On 27 October, the Duke handed the constitutional instruments to Prime Minister Milton Cato formally declaring the country independent.

[8] Despite sharing the same person as their respective monarch, each of the Commonwealth realms — including Saint Vincent and the Grenadines — is sovereign and independent of the others.

[8] The monarchy thus ceased to be an exclusively British institution and in Saint Vincent and the Grenadines became a Vincentian, or "domesticated" establishment.

This legislation limits the succession to the natural (i.e. non-adopted), legitimate descendants of Sophia, Electress of Hanover, and stipulates that the monarch cannot be a Roman Catholic, and must be in communion with the Church of England upon ascending the throne.

[citation needed] Though these constitutional laws, as they apply to Saint Vincent and the Grenadines, still lie within the control of the British parliament, both the United Kingdom and Saint Vincent and the Grenadines cannot change the rules of succession without the unanimous consent of the other realms, unless explicitly leaving the shared monarchy relationship; a situation that applies identically in all the other realms, and which has been likened to a treaty amongst these countries.

[24] The Constitution of Saint Vincent and the Grenadines is made up of a variety of statutes and conventions, which gives the country a similar parliamentary system of government as the other Commonwealth realms.

[27] The monarch's, and thereby the viceroy's role is almost entirely symbolic and cultural, acting as a symbol of the legal authority under which all governments and agencies operate, while the Cabinet directs the use of the Royal Prerogative, which includes the privilege to declare war, and maintain the King's peace, as well as to summon and prorogue parliament and call elections.

[32] The Royal Prerogative further extends to foreign affairs: the governor-general ratifies treaties, alliances, and international agreements.

The monarch, and by extension the governor-general, also accredits Vincentian High Commissioners and ambassadors,[33] and receives diplomats from foreign states.

[34] In foreign policy, the monarch acts solely on the advice of the respective realm government, which can sometimes lead to anomalies in diplomatic recognition.

For instance, in 2022, Elizabeth II as Queen of Saint Vincent and the Grenadines accredited a new Vincentian ambassador to "His Excellency Nicolás Maduro Moros President of the Bolivarian Republic of Venezuela", whereas, she, as Queen of the United Kingdom, recognised Juan Guaido as Venezuela's head of state.

[39] The viceroy additionally summons, prorogues, and dissolves parliament; after the latter, the writs for a general election are usually dropped by the governor-general at Government House, Kingstown.

Thus, bills begin with the phrase: "Be it enacted by the King's Most Excellent Majesty, by and with the advice and consent of the House of Assembly of Saint Vincent and the Grenadines and by the authority of the same, as follows".

[42] The Royal Assent, and proclamation, are required for all acts of parliament, usually granted or withheld by the governor-general, with the Public Seal of Saint Vincent and the Grenadines.

[47] The governor-general, on behalf of the Vincentian monarch, can also grant immunity from prosecution, exercise the royal prerogative of mercy, and pardon offences against the Crown, either before, during, or after a trial.

[48] Any attempt to kill the monarch or the governor-general is considered "high treason", and the person guilty of the offence is sentenced to death.

"The Crown of St. Edward appears on the police force's badges and rank insignia, which illustrates the monarchy as the locus of authority.

[56] In 1959, the Les Jolies Eaux villa on the island of Mustique was given as a wedding present to Princess Margaret by Colin Tennant, later Lord Glenconner.

The Duke visited the Botanical Gardens in Kingstown, the Liberty Lodge Boys Training School and a banana farm in Mesopotamia Valley.

The Prince visited Kingstown's Botanic Gardens, and the Vermont Nature Trail, where he unveiled a dedication to The Queen's Commonwealth Canopy.

At the Saint Vincent and Grenadines Coastguard, the Prince met young people who had recently completed the Youth Development Summer Programme.

At the Botanical Gardens, the Prince planted a Soufriere Tree, the national flower of Saint Vincent and the Grenadines.

At the Botanical Gardens, the couple met local school children and planted a tree to mark the Queen's Platinum Jubilee.

[79] In May 2023, around the time of the coronation of King Charles III, Gonsalves labelled the monarchy "an absurdity" which wished to end in his lifetime,[80] while a poll by Lord Ashcroft found that 63% of Vincentians supported the continuation of their monarchy and 34% preferring an elected head of state, with the majority saying that the King and the royal family "care a lot" about Saint Vincent and the Grenadines.