Victoria will ban ACT residents from entering, with the state declaring the territory as a red zone along with all of NSW.
Both ACT and NSW residents will not be able to enter Victoria from 11.59pm on Sunday, unless they have an exemption.
Victorian residents in either the ACT or NSW will be required to quarantine for 14 days upon their return.
The ACT has been shut off from Victoria, despite the fact there are no active cases in the territory and it has been a year since the ACT recorded its last case of community transmission.
ACT Chief Minister Andrew Barr said it was "incredibly disappointing and frustrating" states had closed their borders to Canberra.
"Canberra is not part of Greater Sydney," Mr Barr posted on Twitter.
"At this time, there is very little justification to consider the ACT as a Covid-affected jurisdiction that requires the highest level of travel restrictions.
"We are asking all states to remove the restrictions on the ACT as soon as possible."
A statement from the Victorian government said health authorities were concerned about the risks of transmission outside Greater Sydney.
"With case numbers continuing to increase in New South Wales, Victorian public health authorities are concerned about the risks of transmission beyond current red zones in Greater Sydney and surrounds," the statement said.
People who have been in Greater Sydney and returned to the ACT are required to undergo a two-week home quarantine, under strict new requirements that came into effect on Friday.
After more than a year without local covid cases, it is incredibly disappointing and frustrating that state borders are again being shut to Canberrans.
— Andrew Barr MLA (@ABarrMLA) July 11, 2021
Canberra is not part of Greater Sydney.
Earlier on Sunday, Victoria Premier Daniel Andrews flagged the NSW border would be closed and urged Victorian residents to return.
"Don't delay, come back today. If you're coming home, then you better be quick about it," Mr Andrews said.
South Australia and Western Australia have also banned ACT residents from entering.
Earlier this week, Mr Barr had also urged his state counterparts to drop border restrictions with the territory.
"Through a combination of good management and good luck, we have had very few Covid cases," he said on Thursday.
"This should be acknowledged by other jurisdictions. I have made this point at national cabinet and bilaterally with almost all other jurisdictions at various points during the last 16 months."
