score:5
Yes.
There are currently no restrictions on travellers from Australia entering the UK. See the list of exempt countries here https://www.gov.uk/guidance/coronavirus-covid-19-travel-corridors.
You must complete a passenger locator form before you arrive in the UK from any country https://www.gov.uk/provide-journey-contact-details-before-travel-uk and you should check the area(s) where you will be staying for local restrictions. Certain areas are currently classified as Very High under the newly-introduced Local Alert framework https://www.gov.uk/guidance/local-covid-alert-levels-what-you-need-to-know
Australian Covid restrictions mean that Australian citizens and permanent residents can only leave Australia if they have an exemption. Applications for an exemption should be made at least two weeks, but not more than three months before the planned travel date. If granted an exemption, evidence of that exemption decision must be taken with you to the airport. https://covid19.homeaffairs.gov.au/leaving-australia