Peter Malinauskas will become South Australia's 47th premier after leading Labor to a historic victory.
Mr Malinauskas will become the first leader to defeat a sitting government since the pandemic began — ousting the Liberal government after just one term.
The shock defeat has seen the Liberals lose five seats — Adelaide, Newland, Davenport, King and Elder — and has left some senior ministers' seats in doubt.
ABC election analyst Antony Green has predicted Deputy Premier Dan van Holst Pellekaan and Child Protection Minister Rachel Sanderson will lose their seats, and outgoing premier Steven Marshall's seat is threatened.
Mr Malinauskas opened his victory speech by acknowledging he is on Aboriginal land.
"I affirm to each and every one of you here and the people across our state that I very much look forward for the first time in the history of our federation, having an initiated Aboriginal man [Kyam Maher] leading our state's Aboriginal affairs movement, but also actively delivering on a state based voice, treaty and truth for the Aboriginal people of our state," he said.
Mr Malinauskas thanked South Australians and said the "significance of the privilege and the size of responsibility" was not lost on him.
"I think sometimes on election nights when governments change hands, that the successful party can confuse the elation of electoral success with an inflated sense of achievement," he said.
"Naturally, people of South Australia and Labor are right to feel satisfied tonight.
Mr Malinauskas spoke about the state's pandemic recovery, highlighting investment in education, training and skills, clean energy, and health.
"We get one shot to recover from a global pandemic as a state and a nation," he said.
"Let them say that we took this opportunity to deliver an economy that left no-one behind.
"Let them say, that we took this opportunity to invest in education, training and skills so that every young person could fulfil their potential.
"Let them say, that this generation realised the opportunity of a clean energy future and all the jobs it can provide.
"Let them say that we had a generational investment in health and mental health to ensure that when people call triple-0, the ambulance rolls up on time.
"Let them say in this moment, this most unique of occasions, that this generation decided not just to think about the next four years, but for the next generation, to live out on that truly egalitarian Australian ideal that we care for other others more than we care for ourselves."
Labor lost the 2018 election after 16 years in power.
Outgoing premier Steven Marshall said he had spoken to Mr Malinauskas and conceded.
"I feel grateful that we live in a democracy where everybody gets their vote and today the people of South Australia have spoken, they've elected a new government," he said.
"But it doesn't take away from the work we have done in South Australia over the last four years."
Mr Malinauskas said Mr Marshall's concession call was "utterly generous, gracious and it was done with the class that we have become incredibly familiar with", and thanked Marshall for his "significant contribution to his party and to our state".
He said the Liberals "may be our adversary, but they are not our enemies".
"We thank them on what is a significant night for them too," he said.
