The Walkley Award winner lwas a journalist for 50 years, including 37 years at the Nine Network.
Colleagues and fans have taken to Twitter to pass on their condolences.
Harvey announced his cancer diagnosis in October after falling ill on a trip to Italy, where he was celebrating his 45th wedding anniversary with his wife.
He publicly vowed to fight the illness and underwent chemotherapy while continuing to report for Nine News' Sydney bureau and present 60 Minutes.
He said in an interview with Nine News Sydney presenter Peter Overton last year that he would fight the illness as hard as he could.
"You stand up to this thing and keep going as long and as hard as you possibly can," he said.
He was too unwell to work in the past week but on the latest episode of 60 Minutes he sent a message of thanks to his fans for their support.
Harvey became a household name after launching his television career with the Nine Network in 1975.
He worked as chief reporter of Nine's Canberra bureau, reporting on the 1975 dismissal of the Whitlam government, before becoming the station's News Director.
He joined the network's Sydney team in 1997 and started presenting the popular Mailbag segment on 60 Minutes in 2003
Harvey started his career as a newspaper journalist with Sydney's Daily Telegraph and in 1964, at the age of 20, won a Walkley Award for a report on a gangland shooting.
He went on to work for the American Newsweek magazine in the late 1960s and reported on the Vietnam War.
Harvey later moved to England to work for the Guardian and in 1973 was named British Reporter of the Year for a series of stories about corruption in government departments.
Harvey remained upbeat in the weeks leading up to his death.
On February 14 he tweeted: "Just came back from another chemo session - the nurses who work with cancer patients are truly amazing and dedicated."
But in January he wrote in The Australian Women's Weekly he was aware of how serious his illness was.
"I'm not kidding myself about how serious the threat from pancreatic cancer is," he said.
"It's deadly serious, but I'm spending my time living in the day. Worrying about tomorrow is not only futile, it can steal today from me."
He is survived by his wife Anne and children, Adam and Claire.
TRIBUTE FROM NINE CEO DAVID GYNGELL
It's with a heavy heart that I confirm the passing of the great Peter Harvey.
As all of you know, Peter had been battling terminal illness for the past six months. And as we all witnessed, he confronted the inevitable with his trademark mix of courage, selflessness and humour.
That was simply inspiring. But not the least bit surprising.
And it was the mark of the man that Peter insisted on coming to work and fronting the cameras right to the end - always grateful of ours and the literally thousands of well wishes from the public, but actually embarrassed about being the centre of so much ' fuss'. As usual thinking little of himself and much more of others, principally his beloved family.
On behalf of everyone at Nine I extend our heartfelt sympathies to Peter's wife Anne and their children Claire and Adam. Their loss is profound and our thoughts and prayers are with them.
Likewise, this is the saddest of days for the Nine Network. Peter Harvey - Harves as he is known to everyone - is and will remain an indelible part of Nine. Like Tony Greig who we also lost so sadly recently, Peter was a huge chunk of
the DNA of this place. He will consequently always be a legend at Nine.
Harves has been with us since way back in 1975. A remarkable 38 years in which he brought his gravitas, understanding, authority and humour to every story he touched.
From the Whitlam dismissal of that first year, through two amazing decades reporting federal politics before switching bases to Nine in Sydney from where he travelled far and wide, covering everything from the Gulf War, to famine in Africa, the ninetieth anniversary of Gallipoli, the overthrow of the Marcos administration in the Philippines to the quirky human interest local stories only he could do justice.
And everything in between. He reported from every continent and invariably did so with distinction. And for the past ten years in addition to his News duties, Harves became the one-of-kind mailbag segment man for 60 Minutes with his unusual and laser-accurate take on news and public debate.
In short, there's pretty much nothing Harves hasn't done, and certainly nothing he hasn't done really well. He'll be remembered fondly forever for his famous deep-throated ' Peter Harvey, Canberra' sign-off of course, but for much, much more .
Peter's legacy will be his continuous highly quality award-winning journalism for the better part of five decades, and the huge respect of his peers across Australian journalism and politics.
And that of young journalists wherever he worked, for whom his time, advice and warmth was legendary.But beyond that, Peter Harvey so clearly won the respect and friendship of his audience - the millions of people who came to trust him, and enjoy what he did and the special way he did it.
Australians can pick a good bloke. And they found one in Harves. Indeed, the best of the best.
He was a larger-than-life figure. A wonderful story teller and a lovable, generous big bloke with a huge heart and that distinctive one-in-a-million voice.
A man who loved his family above all, then his craft which he honed to an art form, and then his colleagues. And who could laugh at himself and the rest of us, and make us all smile.
Peter Harvey will be fondly and deeply missed.
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