Singapore is a parliamentary representative democratic republic whereby the president of Singapore is the head of state, the prime minister of Singapore is the head of government, and of a multi-party system. Executive power is exercised by the Cabinet from the parliament, and to a lesser extent, the president. Cabinet has the general direction and control of the government and is accountable to Parliament. There are three separate branches of government: the legislature, executive and judiciary abiding by the Westminster system. Singapore has been described as being a de facto one-party state.

Legislative power is vested in both the government and the Parliament of Singapore. The legislature is the parliament, which consists of the president as its head and a single chamber whose members are elected by popular vote. The role of the president as the head of state has been, historically, largely ceremonial although the constitution was amended in 1991 to give the president some veto powers in a few key decisions such as the use of the national reserves and the appointment of key judiciary, Civil Service and Singapore Armed Forces posts. They also exercise powers over civil service appointments and national security matters.