For the past seven months, the only people allowed into WA have been required workers and those granted limited exemptions on compassionate grounds.
But WA borders reopened on Saturday, with Peel MP's overwhelmingly supportive of the move.
Under the new regime, anyone will be let in as long as they complete a G2G application and adhere to health requirements.
People who have recently been in NSW or Victoria will be required to enter self-quarantine at a suitable premises, and South Australians have been locked out.
Mandurah MP David Templeman said the decision to begin a controlled border was the right move.
"The recent decision to replace the hard border with a controlled border has been informed by health advice," he said.
"This has been welcomed by many across WA and in other states and territories, with many families and loved ones now able to safely reunite."
His Murray-Wellington counterpart, Robyn Clarke agreed as she said the controlled border would open more avenues for jobs.
"This will open up another avenue for tourism and agricultural workers to come into WA from other parts of Australia," she said.
Many families and businesses in the Peel region have made huge sacrifices to help protect our community.Canning MP Andrew Hastie
Meanwhile, Canning MP Andrew Hastie said Peel families and businesses had made sacrifices to keep the community safe over the past seven months.
"When medical advice supports border restrictions, that advice should be respected - however borders cannot stay closed indefinitely," he said.
"Many families and businesses in the Peel region have made huge sacrifices to help protect our community - it is no small thing to deny an Australian citizen movement within Commonwealth borders and we should jealously guard one another's liberty.
"Borders are no substitute for a strong public health response based on testing and tracing capabilities and strong social distancing principles."
Following a COVID-19 outbreak in Adelaide, the state government moved swiftly to close the border to South Australia.
This has left many people concerned about the possibility of an outbreak in WA, with Dawesville MP Zak Kirkup saying it was alarming that frontline workers are anxious.
"I think the state government has done the right thing in responding to safety concerns, he said on Channel Seven's, Flashpoint.
"Ultimately in the Liberal party our first priority is making sure to keep WA safe - it's a credit that the government have responded quickly.
"The most alarming thing that I've heard is the fact that we have the Australian Medical Association and the Nurses Federation tell us their frontline workers are not confident."
Since South Australia's COVID-19 outbreak, Premier Mark McGowan said if the health advice recommends a hard border, "it will return".
"Bringing back the hard border altogether is under serious consideration, especially given the number of people from South Australia that have been travelling around," he said.
"The evolving situation in South Australia highlights why we need to remain cautious and vigilant in our approach to protecting our state," Mr Templeman added.