Western Australia will reopen its borders to all states and territories from November 14, but some restrictions will remain for people from NSW and Victoria.
Premier Mark McGowan says it is the right time to move to a new "controlled interstate border" after a fall in COVID-19 cases across the country.
For the past six months, the only people allowed into WA have been required workers and those granted limited exemptions on compassionate grounds.
Under the new regime, anyone will be let in so long as they complete a G2G application and adhere to health requirements.
People who have recently been in NSW and Victoria will be required to enter self-quarantine at a suitable premises.
They will also be required to undertake COVID tests on day 11 of their quarantine period and upon arrival if deemed necessary.
Arrivals from all other states and territories - deemed "very low risk" jurisdictions - will not be required to quarantine but must undergo health screening, a temperature check and prove they haven't recently been in NSW or Victoria.
"I want Western Australians to know that we would not be proceeding down this path unless we had the clear health advice to do so," Mr McGowan told reporters on Friday.
"The time is right, the conditions are right, and I'm very confident our control border arrangements strike the right balance."
The decision was signed off by the state disaster council on Friday after receiving the latest advice from the chief health officer.
Mr McGowan says the trigger for moving to the new border controls will be a 14-day rolling average of less than five community cases.
This is currently being achieved in all states and territories.
But the premier warned any significant change in conditions in the eastern states over the next fortnight could force a delay.
"I will have no hesitation to reintroduce the hard border if that's what needed to protect the health of West Australians," he said.
Anyone who failed to declare recent travel to NSW or Victoria could face criminal charges, he said.
The quarantine requirement for those states will be removed once they go 28 days with no community spread, as all other jurisdictions have achieved.
State and federal Liberal MPs and business groups have long called for greater certainty on WA's borders, while the tourism industry warns it has lost $2.4 billion since the state was closed to interstate travellers in early April.
Polls have shown most West Australians wanted the premier to set a date for reopening state borders.
Billionaire mining magnate Clive Palmer is set to challenge the constitutionality of the border closures in the High Court next week.
"We will still fight that case very hard," Mr McGowan said.
"We've still got a controlled border. This is still unprecedented territory."
