Western Australia will reopen its borders to NSW and Queensland from Monday but travellers will still be required to self-isolate for 14 days and get a COVID-19 test.
The decision to reclassify the states as "low risk" means travellers will no longer require exemptions to enter WA.
Queensland has recorded 11 consecutive days of no locally acquired COVID-19 cases and NSW five.
Victoria was also reclassified as a low-risk state earlier this week. People from all other states and territories are allowed to enter WA without self-isolating.
WA's chief health officer has advised Queensland could also transition to "very low risk" from February 1, removing the isolation requirement.
"The outbreak in NSW last month was extremely concerning and prompted immediate action right across the country," Premier Mark McGowan said in a statement on Friday.
"Queensland's situation which followed shortly after was compounded with the detection of the variant strain and again resulted in swift action by us, by the QLD government itself and from other states and territories in a bid to protect the country.
"Everyone in the community has played a role in keeping WA safe and I want to thank them for their co-operation, particularly over the last month as border controls have had to change quickly."
All arrivals at Perth Airport will be required to undergo health screening and a temperature check and to present for a COVID-19 test on day 11 of their isolation period.
Health Minister Roger Cook urged West Australians to continue observing good hygiene practices and using the SafeWA app when they go out.
The latest round of testing at six wastewater treatment plants across Perth has revealed no unexpected detection of the virus.
Inactive viral fragments were detected at the Subiaco plant but Mr Cook said that was expected because of its location near Perth's quarantine hotels.
"The wastewater testing program is providing an additional layer of surveillance for COVID-19 in Western Australia," he said.
"But it does not replace the crucial need for testing people with symptoms of COVID-19 which is the cornerstone of any COVID-19 strategy."
WA reported two new cases on Friday, both returned overseas travellers in hotel quarantine.
Twelve active cases are being monitored.
WA Health has identified a total of 11 cases linked to the highly contagious UK and South African strains of the virus but none are new.
Australian Associated Press