Only children under the age of 12, NT residents, a small number of essential personnel and people arriving on compassionate grounds will be able to access an exemption under some of the country's strictest rules, which will come into effect on Monday.
"Previously, arriving from a green zone you didn't have to be vaccinated," Chief Minister Michael Gunner said today.
"On Monday that route is closed."
Gunner said the small number of unvaccinated travellers would still need to isolate on arrival and get tested.
"It makes no sense for Territorians to do the right thing and get the jab only for us to keep letting in people from interstate who have not yet done the right thing," he said.
The new policy comes as the Northern Territory records one new case of coronavirus.
A 31-year-old fully vaccinated Aboriginal woman from the remote community of Robinson River tested positive to Covid-19 while in quarantine, taking the Territory's cluster total to 26.
It also reflects the Territory's government's embrace of vaccination requirements as "the way out" of strict lockdowns.
Gunner said the current outbreak, stemming from an unvaccinated arrival from Queensland, was a reminder to stay vigilant.
"If we had stopped her from entering the Territory based on her vaccination status or if we had tested her on arrival, there would be no spread of Covid-19," Gunner said.
"Covid would not have made it into Katherine and it would not have made it into a remote community.
"We wouldn't have an elderly Aboriginal woman in hospital on oxygen right now. A three-week-old baby would not have the virus: no outbreak, no lockdowns, no lockouts, no masks.
"If you're eligible to be vaccinated, and you are not fully vaccinated, you are no longer welcome in the Territory, no matter where you're coming from."
Gunner said fines would be issued to people who arrived at the airport without proof of being fully vaccinated, and if you "rock up at a road border, you'll be turned around".