Bolger led the National Party to a landslide victory—the largest in its history—in the 1990 election, allowing him to become prime minister on 2 November 1990.

However, shortly after taking office, his government was forced to bail out the Bank of New Zealand and as a result reneged on a number of promises made during the election campaign.

Bolger continued as prime minister, however his critics argued that he gave the inexperienced NZ First too much influence in his Cabinet.

On 8 December 1997, Bolger was effectively ousted as leader by his party caucus, and was replaced as prime minister by Jenny Shipley.

[5] In 1963, Bolger married Joan Riddell, and they moved to their own sheep and beef farm in Te Kūiti two years later.

[5] In the late 1960s he was asked to accompany the then Minister of Finance Robert Muldoon to see for himself the difficulties faced by farmers in the area.

[1] Bolger entered politics in 1972 as the New Zealand National Party Member of Parliament for King Country, a newly created electorate in the rural western portion of North Island.

However, Talboys was reluctant to openly challenge and the scheme failed with Muldoon reaffirming control after he returned to remain leader.

[16] Initially Bolger pursued a pro law and order approach, with a focus on critiquing Labour's perceived reluctance to combat "lawlessness" and offering a referendum on the reintroduction of capital punishment.

[21] Bolger's Finance Minister, Ruth Richardson, implemented drastic cuts in public spending, particularly in health and welfare.

[22] Richardson also introduced many user pays requirements in hospitals and schools, services previously free to the populace and paid for by the government.

[21] Another major controversial piece of legislation was the 1991 Employment Contracts Act which effectively dismantled the industrial relations settlement that had persisted since 1894.

Bolger had originally proposed a return to a bicameral system, with a Senate elected by Single Transferable Vote,[19] but retreated from this in the face of support for electoral reform.

Following this election result Bolger expressed the need to work with other political parties and decided to demote Richardson from her post, appointing Bill Birch who was seen as more moderate.

During the 1994 Address-in-Reply debate, Bolger argued in favour of a New Zealand republic, but denied that his views related to his Irish heritage.

[29] In April 1995 the Cave Creek disaster gained public attention after a scenic viewing platform collapsed, killing fourteen people.

Bolger initially attacked the report produced by the Commission of Inquiry, arguing that the platform failed "essentially because it lacked about $20 worth of bolts to hold it together".

Bolger's second term would also see France resume nuclear testing on Moruroa, prompting swift condemnation from New Zealand and other Pacific nations.

Proposals to end the status of the Judicial Committee of the Privy Council as the country's highest court of appeal failed to gain parliamentary sanction during Bolger's premiership (however Helen Clark's Fifth Labour Government would replace the right of appeal in 2003 when it set up the Supreme Court of New Zealand).

Although National remained the largest single party, neither Bolger nor Labour leader Helen Clark could form a government on their own.

He also allowed Peters full latitude to select ministers from New Zealand First, unusual for a junior coalition partner in a Westminster system.

These settlements aimed to address longstanding issues related to land and resource rights, contributing to the reconciliation process between the government and Māori communities.

When Bolger returned to New Zealand, he found that Shipley was not only preparing a leadership challenge, but had marshaled enough support to oust him as party leader and prime minister.

And, as many civil servants discovered to their cost, his image of being a simple King Country farmer did not mean that he would not understand their reports and unfailingly point to the flaws in them.

"[33] Bolger retired as MP for Taranaki-King Country in 1998, prompting the 1998 by-election and subsequently became New Zealand's Ambassador to the United States.

In response, Bolger acknowledged his involvement in privatising New Zealand Rail, remarking that "my life is full of ironies,"[36] and added that "the world has changed.

[43] Bolger received the Order of New Zealand without the customary knighthood bestowed on former prime ministers, as he supports eliminating honorary titles.