Queensland's border will reopen to Victoria on 1 December, while Tasmania's will do the same on 27 November as South Australia's pizza bar cluster grows.
Victoria is one day from eliminating coronavirus after its streak of no new cases extended to 27.
Testing numbers also remained strong on Thursday, with 12,862 in the previous 24 hours.
Health authorities regard 28 days with no new cases as elimination of the virus in the community, given that represents two 14-day incubation periods.
It's been a significant week for Victoria, with its last active case on Monday.
Meanwhile, NSW on Thursday recorded no new cases of COVID-19 - locally or in returned travellers - for the first time in almost two months.
The last time the state hit this milestone was on 27 September.
It comes as the Victoria's hotel quarantine system will restart for international arrivals on 7 December, with Premier Daniel Andrews all but ruling out the option of home quarantine.
Interim recommendations into the state's botched hotel quarantine program had recommended it use a combination of home and hotel-based quarantine, including electronic ankle or wrist bracelets to monitor people at home.
On Thursday, Mr Andrews said the state is "going to have a hotel-based system, but it will look and be different to what it was last time".
He said there was no consensus in national cabinet as to how the states should run hotel quarantine, adding he did not want to run the risk of further border closures.
The NSW border with Victoria has already reopened, while Queensland and Tasmania have announced they will both reopen their borders to the state in the coming days.
The border restrictions in Queensland will relax on 1 December, while Tasmania will allow Victorians in from Friday.
Queensland's announcement came a day after Premier Annastacia Palaszczuk revealed travel from Greater Sydney will also be permitted from 1 December.
"During the forthcoming Christmas school holidays, I think we will see now, with the borders opened to New South Wales and Victoria, we will see the Gold Coast and places like Cairns and the Whitsundays now doing a roaring trade," she told ABC News Breakfast on Wednesday morning.
"That is great for Queensland businesses, it's great for Queensland tourism, it's great for our theme parks.
"I encourage people, there's no better place to spend your Christmas holidays than Queensland."
Mr Andrews said he would encourage people to stay in Victoria over the summer to support local businesses.
"There's lots of great ways to stay at home this Christmas and this summer and support Victorian businesses," the Victorian premier said.
"But look, this is a triumph for the people of Victoria. We had a clear strategy. Everyone made sacrifices. We stayed the course and now we have no active cases, no new cases."
Queensland's Chief Health Officer Jeannette Young said authorities were carefully watching the recent outbreak in South Australia and would soon make a decision on that border.
"South Australia - we're still waiting to see how their outbreak unfolds," she told reporters.
"It's been really good so far. They've had only small numbers. We just have to see what happens in that first incubation period."
New cases in South Australia linked to Parafield cluster
Meanwhile, South Australia's COVID-19 cluster has continued to grow, with a school student and another man testing positive to the virus.
Chief Public Health Officer Nicola Spurrier confirmed on Thursday that a student from Woodville High School, who tested positive late on Wednesday, became infected after visiting the Woodville Pizza Bar - a known hotspot.
Professor Spurrier said the student collected takeaway from the pizza bar on 14 November when a person known to be infected was working.
She said health authorities were investigating how infectious the student was when she attended school on Monday, but said all students, teachers and their families have been asked to isolate.
"I am strongly of the belief that nothing has been done that was wrong," she said.
The school has been closed for deep cleaning until further notice.
The other new virus case was a man in his 40s who was already in quarantine as a close contact of an earlier case.
The Parafield cluster now stands at 31 cases, with about 4,800 people in quarantine.
Tasmania relaxing border restrictions
Tasmania’s border will reopen to Victorians on Friday for the first time in more than eight months.
After previously flagging a 27 November reopening, the island state's premier confirmed mandatory quarantine requirements for Victorian arrivals would end from 12:01am.
"I want to commend the efforts of Victorians for getting on top of COVID-19," Peter Gutwein said in a statement on Wednesday.
"We look forward to welcoming Victorians back to Tasmania. This will be welcomed by so many who have been waiting months to reunite with loved ones."
Victorian travellers will be required to undergo health screening when they arrive in Tasmania, in line with protocols for all visitors.
Tasmania will be open to all states and territories bar SA.
Mr Gutwein said an update about SA restrictions would be provided on Thursday.