On Monday, the National leader gave Governor-General Dame Cindy Kiro an assurance that his government could "command the confidence" of parliament, paving the way for his ministers to be sworn in.
The assurance was possible after weeks of negotiations with minor parties ACT and New Zealand First produced a three-way coalition government.
Dame Kiro signed ministerial warrants for all 30 ministers, who then offered oaths or affirmations underneath a stately photo of King Charles III.
Like most of his ministers, Mr Luxon opted to swear an oath rather than a non-religious affirmation, doing so while holding a bible and including the phrase; "so help me God".
"A very special day, the swearing in of a new cabinet and a new ministry, and a very special day for our new ministers and the families to be here," he said.
The ceremony marks the end of the post-election negotiations, and begins Mr Luxon's administration.
Prime Minister and National leader Chris Luxon will head a three party coalition. (Ben McKay/AAP PHOTOS)
The 53-year-old will lead the coalition, with his National party deputy Nicola Willis holding the all-important finance portfolio, akin to Australia's treasurer post.
Mr Luxon said he would host his first cabinet meetings on Tuesday and Wednesday.
"Our focus for this week is to have our 100-day plan of action and have that signed off," he said.
Mr Luxon also said he planned to visit Australia before Christmas for his first official trip as New Zealand's leader.
Earlier on Monday, outgoing Prime Minister Chris Hipkins made a private visit to Government House to resign his commissions, beginning life as opposition leader.
"I wish Mr Luxon and his coalition partners well," he said.
The government is New Zealand's first coalition featuring three parties in cabinet.
Under the deals brokered, it also boasts another first: a time-shared deputy position.
NZ First leader Winston Peters will be deputy prime minister until 31 May 2025 under the pact, with ACT leader David Seymour taking over from that date until the end of the parliamentary term.
The two party leaders famously don't get on.
Mr Seymour vowed not to share a cabinet table with Mr Peters, who he has called a "clown", a "crook", "grandpa" and "the least trustworthy person in New Zealand politics".
Mr Peters, 78, has called Mr Seymour, 40, a "cuck" and a "chihuahua", and on Friday, refused to say whether he trusted Mr Seymour.
On Monday at least, it was all smiles as the triumvirate shared the ballroom Government House for their swearing-in.
The 20-strong cabinet also breaks new ground for racial diversity.
There are a record seven Maori ministers - National's Shane Reti and Tama Potaka, ACT's Mr Seymour and Nicole McKee, and NZ First's Mr Peters, Shane Jones and Casey Costello.
Two ministers - Mr Jones and Mr Potaka - spoke their oaths in te reo Maori, the indigenous language, while Melissa Lee spoke partially in Korean.
There is less representation of women in the parliament and ministry.
There are eight women and 12 men in cabinet, a touch below the parity achieved earlier this year under the Labour government.
Fewer women were elected in this parliament overall: 56 MPs of the 123-member house.
There are also no members of the new cabinet who are openly LGBT, with just one member of the rainbow community among the 68 MPs from government parties.
ACT MP Todd Stephenson, who left long-term employment in Australia to return to New Zealand after being preselected, lives in Queenstown with his husband Alex.
The drop-off in government LGBT MPs means New Zealand no longer has the most queer parliament in the world - a title it held after electing 12 openly LGBT MPs at the 2020 election.
The three government parties have also failed to elect a single MP of a Pasifika background, with overall parliamentary representation dropping from 11 to five MPs.Â
