The new leader is 53-year-old MP Michael McCormack from the New South Wales seat of Riverina. But in a surprise, Mr McCormack had to withstand a challenge from Queensland MP George Christensen.
Veterans Affairs Minister Michael McCormack, as expected, has been chosen as the new leader of the National Party and becomes the country's deputy prime minister.
But what was expected to be a straightforward, unopposed election did not turn out that way.
Outspoken MP George Christensen, who called for the Nationals on Sunday to end their 95-year coalition with the Liberal Party, contested the leadership, too.
National Party whip Michelle Landry announced the outcome of the vote shortly after a party-room meeting (mon) in Canberra.
"George Christensen and Michael McCormack put their names forward, and Michael McCormack is now the new leader. So that's, uh, surprising. And I'd also like to say I've bought myself a new whip this week to keep the boys in line in the party room!"
So who is Michael McCormack?
The little-known MP was elected to parliament in 2010.
In the 1990s, he described homosexuals as "sordid" and blamed them for AIDS in a column he wrote as the editor of The Daily Advertiser newspaper in his home town of Wagga Wagga.
He has since apologised for the comments.
And as small-business minister, he was tasked with taking the census online for the first time in 2016 but the process was plagued by major technical failures.
Mr MrCormack's ascension to the leadership had been expected to be formality with the 53-year-old as the only candidate, so Mr Christensen's decision to nominate for the job came as a surprise.
The challenge broke the National Party's no-contest tradition for the first time in 18 years.
Ms Landry refused to reveal the vote split, but Mr Christensen has since released a statement offering Mr McCormack his "sincere congratulations."
Mr McCormack, speaking shortly after the ballot, insists he is not just keeping the leadership warm for former leader Barnaby Joyce to make a comeback.
"I have been elected to do the job by the National Party. As I said, Barnaby Joyce will play an important part in our party and in our nation going forward, and I look forward to working with him to overcome some of the challenges that are faced by rural and regional people. We have always done that. I've always been good mates with Barnaby. And, in fact, I've been kicked out of parliament for defending him a bit too vigorously at times. But I'll certainly, certainly make sure that we're very close, and we're going to continue to work as a team, not as individuals but as a team, going forward."
Mr Joyce quit as leader of the party and deputy prime minister after weeks of controversy surrounding his extramarital affair with former, now-pregnant staffer Vikki Campion and ensuing controversies.
He says he will move to the backbench.
Nationals MP Darren Chester has told Sky News he thinks it is ridiculous to be talking of a Barnaby Joyce comeback.
"Barnaby's indicated himself he's going back to the backbench. He's got things he wants to do in terms of his own personal life, in terms of representing the New England electorate. I just think it's kind of a ridiculous question to be putting on the day we just picked a new leader. In my time in this place -- I've been here 10 years now -- in my time in this place, I've found Barnaby is someone who has always put the interests of regional Australians and the Nationals first and fought hard for our team and fought hard for regional people. I see no reason why that would change."
Mr McCormack has been sworn in as the National Party leader and deputy prime minister.
Prime Minister Malcolm Turnbull, just back in the country after a whirlwind visit to the United States to meet US president Donald Trump, met his newly elected deputy after the ceremony.
Mr Turnbull described Mr McCormack as a strong advocate for rural Australia.
And in the wake of George Christensen suggesting the Nationals should end their coalition with the Liberal Party, Mr Turnbull and Mr McCormack say they look forward to continuing the partnership.
(Turnbull:) "The Liberal Party has been in partnership with the Nationals for all of its life. And if you include the predecessor parties to the Liberal Party, it's a political partnership that's 95 years old. So that's quite an innings."(McCormack:) "Quite an innings of achievement and delivery, and we'll continue that."
