His conservative People's Party (ÖVP), revamped by Kurz as a more hardline "movement", agreed late on Friday a coalition deal with the far right that saw him sworn in on Monday.
"Our aims are quite clear. We want to ease the tax burden for people, we want to strengthen our economy, which will bolster our social system," Kurz told reporters late Friday after agreeing the coalition.
"And first and foremost we want to increase security in our country, including by combatting illegal immigration," he said.
The takeover of the ÖVP in May by "Emperor Kurz", with his rosy cheeks, large ears and composure belying his young age, was as swift as it was radical.
First he killed the unhappy coalition with the Social Democrats (SPÖ). Then he rebranded the ÖVP and its black party colour as a turquoise "movement" tough on migrants and easy on taxes.
The strategy of "putting Austrians first" propelled the sluggish ÖVP to pole position in opinion polls and Kurz to near-rock star status.
Wherever he went during the election campaign, fans sporting turquoise T-shirts would chant his name and women asked if they can hug him.
Selfie sessions with Kurz, always in slim-cut suits and tieless white shirts, lasted over two hours.
Observers say there has not been such euphoria over an Austrian politician since Jörg Haider, the magnetic but controversial far-right leader who died in 2008.
In slick campaign adverts where he is scaling the Alps, Kurz promised -- echoing his new partners the far-right Freedom Party (FPÖ) -- to slash taxes and red tape and "return this beautiful country to the peak".
"The time is now," read election posters with Kurz staring into the distance.
His appeal as an agent of change is remarkable given that he has been a key cog in the political machine he now seeks to overhaul.
The only child of a secretary and a teacher, Kurz joined the ÖVP's youth wing in 2003.
As its chief, he drew ridicule with a 2010 council election campaign featuring the slogan "Schwarz macht geil", or "Black makes you hot".
Kurz posed with skimpily clad girls on top of a black Hummer, the "hot-o-mobile", and distributed black condoms.
This blunder notwithstanding, the former law student -- he never finished his degree -- enjoyed a meteoric rise, becoming secretary of integration in 2011 and foreign minister two years later, aged 27.
Full of praise for Hungary's populist Prime Minister Viktor Orban, Kurz claims credit for closing the Balkan migrant trail in 2016.
The move saw the Austrian named one of the most influential Europeans by the Politico news website.
The private politician -- he is not often seen in public with longterm girlfriend Susanne -- ran a campaign as immaculate as his trademark gelled-back hair, showing a maturity and toughness well beyond his years.
But some critics have accused Kurz of being a "mini-dictator" running the party as a "one-man show".
And analysts have warned that Kurz's election will be an "earthquake" for the European Union, despite his pro-European pledge.
"He's a 'Haider light' version," said Paris-based Austria expert Patrick Moreau, adding that Kurz's ideas on everything from immigration to economic policy represent a "complete rupture" with the EU.
At Friday night's press conference, Kurz and FPÖ chief Heinz-Christian Strache appeared to have struck up a personal rapport -- despite Strache's at times vicious attacks in the election campaign.
But some worry that Kurz has given too much away to the FPÖ, with the far-right party securing the interior, defence and foreign ministries in the coalition deal.
Political analyst Thomas Hofer said the fact that all of Austria's security services will now be controlled by the FPÖ "will draw some criticism".
But Hofer added that Kurz wanted to ensure that unlike his party's previous "grand coalition" with the centre-left, this administration will not become gridlocked.
"What he wanted to achieve is that both parties have their real responsibilities. In previous governments the parties blocked each other and Kurz wants to avoid that," Hofer told AFP.