NSW recorded 110 new locally acquired Covid-19 cases in the 24 hours to 8pm yesterday.
A total of 43 people were infectious while in the community.
Nearly 84,000 people were tested in the past 24 hours, which is the highest number of tests NSW has ever recorded in one day.
Premier Gladys Berejiklian said the high number of cases was a reflection of the high number of tests.
"It means we are scooping up all the cases we can find," she said.
Of the new cases, 54 were linked to a known case or cluster and 56 were still under investigation.
There were 37 cases in isolation throughout their entire infectious period and 17 in isolation for part of their infectious period.
There are 106 Covid-19 patients in hospital in New South Wales today, 23 of them are in intensive care.
As of Tuesday night, there were three people in hospital with Covid-19 in Victoria.
South Australia recorded six new community cases of Covid-19, all of them had been at sites that health authorities have described as high risk. Five were at an Adelaide winery that was visited by someone with the virus on Sunday afternoon, the sixth is a child who had been at a Greek restaurant in the city.
Meanwhile, Prime Minister Scott Morrison has said he takes responsibility for Australia's slow Covid-19 vaccination rollout, but said that the country is now tracking well with the vaccination programme.