He held office as leader of the New South Wales division of the Liberal Party of Australia, and assumed the position following the resignation of Gladys Berejiklian.

[20] With the resignation of Barry O'Farrell as premier,[21] and the subsequent ministerial reshuffle by Mike Baird, the new Liberal leader,[8] Perrottet was appointed as Minister for Finance and Services in April 2014.

[6] In the lead up to the 2019 state election, Perrottet attempted to wrest Castle Hill back from Williams, citing work-life balance as Hawkesbury was too far for him to travel.

This was unsuccessful, with Williams retaining the Liberal preselection, and resulted in media reports of significant party infighting and Perrottet publicly apologising.

A combined investigation by The Age, The Sydney Morning Herald and ABC TV's Four Corners found that icare had underpaid as many as 52,000 injured workers by up to $80 million and that the organisation was close to collapse.

[35] Following the investigation, NSW's workers' compensation regulator State Insurance Regulatory Authority (SIRA) announced in August 2020 that it would be applying increased scrutiny to icare's 2020 financial audit.

The report highlighted the deteriorating financial position of the scheme, a fall in return to work rates and an increase in claim costs, including medical expenses.

The committee's chairman said "icare's decision and ambitious approach to implementing a new claims management model has also played a role, to the detriment of injured workers and the public".

During the northern beaches lockdown at the end of 2020, he suggested that the state's chief health officer, Kerry Chant, take a pay cut if Sydney or its suburbs were unnecessarily locked down.

[41] Perrottet also pushed the federal government to reinstate JobKeeper payments for Sydney residents in July 2021 as a new wave of infections was beginning.

[46] In early October 2021, after becoming premier, Perrottet unveiled an accelerated roadmap out of lockdown with some key changes to attendance limits at indoor and outdoor gatherings.

On 3 October 2021, following the resignation of Premier Gladys Berejiklian, Perrottet was nominated to run as NSW Liberal Party leader, with Stuart Ayres, the Minister for Jobs, Investment, Tourism and Western Sydney, as his deputy.

[49] At 39 years of age, Perrottet became the youngest premier in New South Wales history, surpassing the previous record held by Nathan Rees, who was 40 when he first took office.

"[52] In June 2022 the Perrottet government announced plans to fly the Aboriginal flag on the Sydney Harbour Bridge, at the cost of 25 million dollars.

[57] In late July 2022 further controversy emerged over allegations of bullying and mistreatment of staff by then-Fair Trading Minister Eleni Petinos, resulting in her sacking from the cabinet.

[60] Toward the end of September opinion polls showed significant drops in popularity, with Labor establishing a substantial lead over the Coalition—drops widely linked with the fallout from the controversies.

[64] On 12 January 2023, Perrottet revealed that he had worn a Nazi uniform as fancy dress at his 21st birthday, apologising at a media conference after a cabinet minister was made aware of the incident.

Robert Borsak, the leader of the Shooters, Fishers and Farmers Party, argued that this could have potentially broken the Oaths Act, which is punishable by up to 5 years in jail.

[86][44][87] In his maiden speech to NSW Parliament in 2011 he stated a belief in "exercising freedom [so] that individuals can develop the habits of generosity, hard work, fairness and concern for others".