She comes from a working-class mining family in Nottingham, England, left school at 15 when her parents became ill, and trained as a nurse - the first in her family to go to university.
She later completed a doctorate in nursing education and has written at least 12 books on nursing, counselling, mental health and prison health care.
University of Auckland Chancellor Scott St John said Freshwater was chosen after "a comprehensive international search" which included consulting with staff and stakeholders on the required skills and characteristics.
"A values-based leadership style and commitment to Māori and Pacific development, and an understanding of the civic, regional and global relevance of the University of Auckland were critical factors in the selection," he said.
"I believe we have very much met this brief with the appointment of Professor Freshwater.
"Other important considerations were a commitment to innovation – in teaching, research and the student experience, an understanding of the pressures of funding, a competitive, distinctive and ambitious vision for the future, and a strong commitment to role modelling, equity, diversity and inclusiveness from the top."
Freshwater takes up the Auckland job at a difficult time for the university after it dropped out of the world's top 200 universities in the Times Higher Education rankings last year, below the University of Western Australia which was ranked 134th.
When she takes up the job next March she will be one of four women heading half of New Zealand's eight universities, joining Professor Jan Thomas at Massey University, Professor Cheryl de la Rey at Canterbury and Professor Harlene Hayne at Otago.
Born 57 years ago, Freshwater told Times Higher Education in April that she grew up in "a tiny little two-up, two-down – the sorts of places you see in mining towns, with not very much else around.
"Doors left open, kids playing on the street; but we never ventured far to go walking. I don't remember thinking about the beautiful green rolling hills or the limestone crags," she said.
"In my early years I had two younger brothers, a mum in and out of hospital and a father present sometimes," she said in the interview.
"Having to help a lot while I was at school, I'd already learnt to prioritise. In nurse training I was dealing with death as soon as I was 18. You learn to focus on what's important and let other things wash over."
She became a marathon runner as "a fantastic way of balancing life and making sure you look after yourself". She ran the London Marathon seven times.
She moved to the University of Western Australia as deputy vice-chancellor in 2014 and took the top job there in January 2017.
She chairs the Group of Eight leading Australian universities and has been vice-chair of the Matariki Network of seven universities including the University of Western Australia, Otago University and institutions in the United States, Canada, Britain, Germany and Sweden.
University of Western Australia Chancellor Robert French said Freshwater's term at the Perth university "has marked a watershed in the university's recent development history".
"She has played a leading role in the establishment of the UWA Public Policy Institute, focused on the delivery of real-world solutions to challenges in the Indo-Pacific region," he said.
"On behalf of the Senate, I thank her for her tireless work in the interests of the university. I wish her and her family well in the next phase of her career."