The Niue Constitution Act vests executive authority in Her Majesty the Queen in Right of New Zealand and the Governor-General of New Zealand. The Constitution specifies that in everyday practice sovereignty is exercised by the Niue Cabinet of Ministers, comprising the premier and three other ministers. The premier and ministers are members of the Niue Legislative Assembly, the nation's parliament.

The assembly consists of 20 democratically elected members, 14 of whom are elected by the electors of each village constituency, six by all registered voters in all constituencies. Electors must be New Zealand citizens, resident for at least three months, and candidates must be electors and resident for 12 months. Anyone born in Niue must register on the electoral roll. If two candidates have the same number of votes, the votes are recounted; if the number of votes is still equal, the name of the winning candidate is drawn out of a hat. The Speaker is elected by the assembly and is the first official to be elected in the first sitting of the Legislative Assembly following an election. The new Speaker calls for nominations for premier; the candidate with the most votes from the 20 members is elected. The Premier selects three other members to form the Cabinet of Ministers, the executive arm of government. The other two organs of government, following the Westminster model, are the Legislative Assembly and the Judiciary. General elections take place every three years, most recently on 7 June 2008.