Brownlee was born in Christchurch to Leo (a saw miller, who died in 1989) and Mary Brownlee. He is the eldest of five children. His uncle, Mark Brownlee, represented New Zealand in rowing at the Summer Olympic Games in 1964 and 1968, and his cousin Scott Brownlee (Mark's son), represented New Zealand in rowing at the Olympics in 1992, 1996, and 2000.
A Roman Catholic, he attended St Bede's College where he twice failed to gain University Entrance. After leaving high school, he worked in his family's timber business and received training in carpentry. After qualifying as a builder, he retrained as a teacher and taught woodwork, technical drawing and Māori, over a period of twelve years, at Ellesmere College, and at his alma mater, St Bede's.
In the 1993 elections, Brownlee stood as the National Party candidate in the Sydenham electorate, where he campaigned unsuccessfully against Jim Anderton, the Alliance leader. In the 1996 election he contested the nearby seat of Ilam, and won by a comfortable margin. He has remained the MP for Ilam since that point, although his majority declined until making a strong recovery in the 2005 election.
Brownlee's roles as an MP have included serving as the National Party's Junior Whip, shadow Leader of the House, and as the Party spokesperson on superannuation, energy, transport, local government, Māori affairs, state-owned enterprises, state services, and ACC. He was Don Brash's Deputy Leader from 2003–2006, and has served as a minister and Leader of the House in the Fifth National Government. His most prominent role has been leading the Government's earthquake recovery efforts following the 2010, 2011 and 2016 earthquakes.
Brownlee challenged the vacant deputy leadership of the National Party in 2001, but was defeated by Bill English. English eventually succeeded to the leadership later that year. However, by 2003 Brownlee was seen by Labour Party MP Phil Goff and Scoop columnist Paulo Politico as a potential challenger to English's leadership. English was eventually replaced as National Party leader by former Reserve Bank Governor Don Brash. Brownlee was thought to be a possible deputy leader to Brash but declined to pursue the position, which went to Nick Smith.
Shortly after his election, however, Smith opted to take two weeks of stress leave, saying that the protracted leadership disputes had exhausted him. When Smith returned to Parliament, Brownlee challenged him for the deputy leadership. Informed of the challenge, Smith resigned, and on 17 November 2003 Brownlee won the caucus vote unopposed. Initially, Smith alleged that while he was on stress leave, "a campaign to oust me was conducted in the media while I was under the leader's instructions to make no comment." Audrey Young wrote in the New Zealand Herald that Brownlee and Murray McCully were rumoured to have been behind the campaign to oust Smith as deputy leader.
After becoming a deputy leader, Brownlee continued his confrontational and colourful style of political debate. Following the controversy surrounding Brash's Orewa Speech of 27 January 2004, Brownlee became the National Party's spokesman for Maori Affairs in place of Georgina te Heuheu, who resigned from the position after refusing to endorse Brash's comments. Brownlee's approach to this portfolio involved criticising the government's policies regarding perceived special treatment for Māori, an issue at the core of National's 2005 election manifesto.
After the resignation of former National Party Leader of the Opposition Don Brash in November 2006, internal party discussion apparently ensued over the post of deputy leader. Brownlee stepped aside as deputy leader and the new leader, John Key, appointed confirmed him as the third-ranked National Party MP.
Following the election of the Fifth National Government in November 2008, Brownlee was appointed a member of the Executive Council of New Zealand and to Cabinet as Minister of Economic Development, Minister of Energy and Resources and as Associate Minister for the Rugby World Cup. He also became the Leader of the House, making him responsible for the schedule of Government business, allocating time for non-governmental and opposition business to be presented to the house and announcing the Business Statement for the Parliamentary sitting dates to the house and its members.
As the Government's most senior Christchurch-based MP, Brownlee led the Government's work in earthquake recovery after the 2010 and 2011 earthquakes. Following National's re-election in 2011 and 2014, Brownlee additionally served as Minister of Transport, Minister of Defence, and Minister of Civil Defence.
Brownlee was selected to represent New Zealand in London at the funeral of former British Prime Minister Margaret Thatcher.
Brownlee voted against the Marriage (Definition of Marriage) Amendment Bill, a bill allowing same-sex couples to marry in New Zealand.
Brownlee received criticism during the 1999 election campaign when he ejected Neil Able, a 60-year-old Native Forest Action campaigner, from the National Party's 1999 election campaign launch. The ejection took place with what many, including watching journalists, considered excessive force. Neil Able started civil assault proceedings against Brownlee, seeking damages of $60,000. In 2002, a District Court judge found in favour of Mr Able that Brownlee had "used excessive and unnecessary force on Mr Abel when he tried to remove him from a staircase handrail". Brownlee was ordered to pay Neil Able $8,500 in damages. Brownlee later sought unsuccessfully to have $48,000 of his legal fees reimbursed by the Government.
In August 2009, Brownlee was criticised by Forest and Bird Spokesperson Kevin Hackwell for playing down government discussions to possibly allow more mining within conservation areas. Hackwell was reported as stating that "If the Government's to go down this line they could be buying a fight with the people of the Coromandel, with the people of New Zealand generally, who have put these areas aside and want them protected for their conservation values". The New Zealand mining industry was reported as welcoming the move.
In early December 2009, Forest and Bird released a leaked document that included the proposal to remove part of the conservation status of Mount Aspiring National Park to allow mining. The result of the controversy was that the government decided not to explore considerations amongst significant debate on the issue in the House, in submissions to the Select Committees and within the National Party's own parliamentary caucus.
On the withdrawal Brownlee stated "I suspect few New Zealanders knew the country had such considerable mineral potential before we undertook this process, and I get a sense that New Zealanders are now much more aware of that potential". He went on that it might contribute to economic growth and further stated that "New Zealanders have given the minerals sector a clear mandate to go and explore that land, and where appropriate, within the constraints of the resource consent process, utilise its mineral resources for everyone's benefit". An additional announcement from Conservation Minister Kate Wilkinson pronounced that future National Park land would receive protections, stating that, "This is an added layer of protection for New Zealand's most highly valued conservation land..."
After the Canterbury earthquake of 4 September 2010, Brownlee, as the senior Christchurch-based Minister, was appointed Minister for Canterbury Earthquake Recovery on 7 September 2010. The role has given Brownlee substantial powers in supervising and coordinating the involvement of central government, local government, and the private sector in rebuilding Christchurch.
On 14 September 2010, Brownlee introduced the Canterbury Earthquake Response and Recovery Act 2010 into the house with leave to pass the legislation in one sitting. This Bill was passed by the time the House adjourned at 10.02 pm.
In 2012, it was reported that the idea of using part of Christchurch's red zone for an international rowing regatta course known as East Lake had found the support of Brownlee as Earthquake Recovery Minister.
In September 2012, Brownlee accused residents in Christchurch's newly created TC3 zone of "carping and moaning" for comments they made in a survey conducted by the main local newspaper. The comments were about perceived inaction by the authorities, including the government. He apologised soon after.
In March 2012, Brownlee made controversial comments about Finland, after he suggested during a parliamentary session that Finns are uneducated, unemployed murderers who don't respect women. With his comments Brownlee rejected New Zealand Labour Party's plans to model the economy on Finland, and added that Finland "has worse unemployment than us, has less growth than us, can hardly feed the people who live there, has a terrible homicide rate, hardly educates its people, and has no respect for women." Brownlee's comments were debated in Finnish media with Foreign Minister Erkki Tuomioja stating that Finland would not take any action as the comments were clearly a device for internal politics rather than an attack on Finland. He continued to say: "I doubt he even knows where Finland is."
In November 2014 Brownlee was fined $2000 by New Zealand's Civil Aviation Authority for a breach of airport security that occurred at Christchurch Airport on 24 July 2014. An official inquiry found that Brownlee and two of his aides had evaded airport security screening by entering a departure lounge through an exit door while in a rush to board a domestic flight.
In May 2017, less than a week after being appointed as Foreign Minister, Brownlee was publicly corrected by the Prime Minister, Bill English, after claiming that a New Zealand-sponsored United Nations Security Council Resolution on Israel (about settlements in occupied territories) was "premature". The Prime Minister said Brownlee was "still getting familiar" with the language used by his predecessor, Murray McCully, who had authorised the sponsorship of the resolution.
The Prime Minister said he had confidence that Brownlee was clear on New Zealand's position now, a position that had not changed since the Government had chosen to push through the resolution. Brownlee had been a cabinet minister at the time.