John Key led the centre-right National Party to victory in the November 2008 general election and again in the November 2011 elections.
His party's 2008 victory ended nine years of Labour-led government.
The National Party fell short of a parliamentary majority in both the 2008 and 2011 elections and was compelled to form a coalition with other parties.
Born in 1961 and brought up in relative poverty by his Austrian-Jewish immigrant mother after the early death of his father, Mr Key became a currency trader and has acquired a substantial personal fortune.
He rose to be head of foreign exchange at Merrill Lynch in Singapore, and served as a member of the Foreign Exchange Committee of the New York Federal Reserve Bank in 1999-2001.
National Party president John Slater encouraged him to enter politics in 2001, and Mr Key was elected to parliament the following year. He was appointed opposition finance spokesman in 2004, and became party leader in 2006 after Don Brash resigned over allegations of election-funding irregularities.
Since taking over the party, Mr Key has positioned it more on the centre ground. His first speech as leader pledged a future government to measures to prevent the creation of an "underclass", and he has said that reducing greenhouse gas emissions by 50% in the next 50 years will be a priority.
New Zealand has a single-chamber parliament, the House of Representatives, which is elected for a three-year term. Coalition governments have been the norm since proportional representation replaced the "first past the post" electoral system in 1993.