Sir Robert David Muldoon (; 25 September 1921 – 5 August 1992) was a New Zealand politician who served as the 31st Prime Minister of New Zealand, from 1975 to 1984, while Leader of the National Party.
Serving as a corporal and sergeant in the army in the Second World War, Muldoon completed his training as an accountant and returned to New Zealand as its first fully qualified cost accountant.
He was first elected to the House of Representatives at the 1960 general election as the Member of Parliament for Tamaki.
Muldoon served successively as Minister of Tourism (1967), Minister of Finance (1967–1972), and Deputy Prime Minister (1972).
He became Leader of the Opposition in 1974 and soon led the National Party to a decisive victory in the 1975 general election.
Muldoon came to power promising to lead "a Government of the ordinary bloke." He appointed himself Minister of Finance.
His tenure as Prime Minister was plagued by an economic pattern of stagnation, high inflation, growing unemployment, and high external debts and borrowing.
Economic policies of the Muldoon Government included national superannuation, wage and price freezes, industrial incentives, and the Think Big industrial projects.
In foreign policy, Muldoon adopted an anti-Soviet stance and re-emphasised New Zealand's defence commitments to the United States and Australia under the ANZUS pact.
His refusal to stop a Springbok rugby tour of New Zealand divided the country and led to unprecedented civil disorder in 1981.
Muldoon led his party to two additional election victories in 1978 and 1981.
He called a snap election in 1984, in which National suffered a significant defeat to Labour.
Shortly before leaving office, amid a constitutional crisis, Muldoon was forced by the incoming Government to devalue the New Zealand dollar.
In 1984, he was only the second Prime Minister (after Sir Keith Holyoake) to receive a knighthood while still in office.
Muldoon was a polarising figure and has been variously described as a "bully", an "enigma," and "a strong believer in the battler, the little man, the ordinary citizen and his or her rights."