Guyana is a parliamentary republic in which the President of Guyana is both head of state and head of government. Executive power is exercised by the President, advised by a cabinet. Legislative power is vested in both the President and the National Assembly of Guyana. The judiciary is independent of the executive and the legislature.

Executive authority is exercised by the president, who appoints and supervises the prime minister and other ministers. The Cabinet is tasked with aiding and advising the President as it relates to the general control and direction of the government. The president is not directly elected; each party presenting a slate of candidates for the assembly must designate in advance a leader who will become president if that party receives the largest number of votes. The president has the authority to dissolve the parliament. While the Cabinet is appointed by the President, it is also collectively responsible to National Assembly. A successful no-confidence motion against the government obligates president and cabinet to resign and trigger new elections within 3 months. The president can be removed in case of mental incapacity or gross constitutional violations.

Only the prime minister is required to be a member of the assembly. In practice, most other ministers also are members. Those who are not serve as non-elected members, which permits them to debate but not to vote. The president is not a member of the National Assembly but may Address it at any time or have his address read by any member he may designate at convenient time for the Assembly.

Legislative power of Guyana rests in a unicameral National Assembly. In 2001 the makeup of the National Assembly was reformed. Now 25 members are elected via proportional representation from 10 Geographic Constituencies. Additionally 40 members are chosen also on the basis of proportional representation from National lists named by the political parties. The president may dissolve the assembly and call new elections at any time, but no later than 5 years from its first sitting.

Guyana was ranked 6th least electoral democracy in the Americas according to V-Dem Democracy indices for year 2024.

The highest judicial body is the Court of Appeal, headed by a chancellor of the judiciary. The second level is the High Court, presided over by Chief Justice of Guyana. The chancellor and the chief justice are appointed by the president. The Audit Office of Guyana (AOG) is the country's Supreme Audit Institution (SAI).

For administrative purposes, Guyana is divided into 10 regions, each headed by a chairman who presides over a regional democratic council. Local communities are administered by village or city councils. The regions are Barima-Waini, Cuyuni-Mazaruni, Demerara-Mahaica, East Berbice-Corentyne, Essequibo Islands-West Demerara, Mahaica-Berbice, Pomeroon-Supenaam, Potaro-Siparuni, Upper Demerara-Berbice and Upper Takutu-Upper Essequibo.

Race and ideology have been the dominant political influences in Guyana. Since the split of the multiracial People's Progressive Party (PPP) in 1955, politics has been based more on ethnicity than on ideology. From 1964 to 1992, the pro-African People's National Congress (PNC) party dominated Guyana's politics.