Dominic Perrottet says he is "very confident" resuming face-to-face education will go well despite the potential for COVID-19 outbreaks, with some NSW schools already closed for deep cleaning.
"There will be challenges along the way," the premier told reporters in Sydney on Sunday.
"We know that, we've had a number of schools close but the alternative is to keep all schools closed.
"We're not doing that."
The state added 296 locally acquired infections to its COVID-19 caseload on Sunday along with four deaths: two men in their 60s, one in his 70s and one in his 80s.
Kindergarten, year 1 and year 12 students went back to school in NSW last week and remaining pupils will return to classrooms on Monday.
On Friday NSW Education announced seven schools were closing for deep cleaning after positive COVID-19 cases, and a further two were added to the list on Saturday.
Asked about reports up to 160 schools throughout NSW had staffing issues as students returned, Mr Perrottet said he was aware there would be some shortages.
"There will always be teachers and people across our state who just decide not to get vaccinated," he said.
"That's their choice. We believe it's a bad choice but ultimately, that success rate of 95 per cent has helped us get our kids back in the classroom."
Opposition leader Chris Minns said on Sunday he would push the government to provide extra funding for school counselling and tutoring to help kids who might have "skipped a beat" with the recent disruptions to schooling in NSW.
Three of the men who were counted in Sunday's COVID-19 death toll were unvaccinated while one was fully vaccinated.
There have been 498 COVID-related deaths in NSW since June 16 and 554 in total since the start of the pandemic.
Some 480 people with the virus remain in NSW hospitals, 119 of them in intensive care and 67 of those in need of ventilation.
Health officials say almost 67,000 COVID-19 tests were conducted in the 24 hours to 8pm on Saturday.
More than 93 per cent of NSW residents aged 16 or over have now received at least one vaccine dose, while 84.4 per cent have had both jabs.
Among 12-15-year-olds, 77.6 per cent have had their first dose and 48.8 per cent are fully vaccinated.
Meanwhile, Halloween enthusiasts are being warned to keep trick-or-treating COVID-safe next weekend.
"If you and your family are planning to celebrate Halloween this year ... aim to keep the celebrations outside, provide closed packaging for treats and instead of communal lolly bowls consider other ways to distribute your treats," NSW Health's Jeremy McAnulty advised on Saturday.
Australian Associated Press