The NSW Teachers Federation signed the wage deal, which includes a minimum pay increase of three per cent for the next three years, on Monday after months of negotiations.
Schools started late as tens of thousands of teachers engaged in the stop-work meeting to vote on the agreement.
Union president Henry Rajendra said the deal was integral to addressing teacher workforce shortages across the state.
"The working conditions of our profession were very, very difficult," he told reporters.
"What we have now are wonderful opportunities where the employer, finally, after so many years, is offering the profession a genuine sense of respect."
The deal includes flexible working arrangements, three extra pupil-free days at the start of term and a $1000 cost-of-living payment if inflation rises to above 4.5 per cent for the state's 95,000 public school teachers.
"Noting the gendered nature of the teaching profession, where 80 per cent of the workforce are women, we've got significant improvements in terms of leave and working conditions," Mr Rajendra said.
Flexible working arrangements might mean two teachers could split a full-time job in order to fill critical gaps in the workforce.
Schools were also left to fend for themselves for professional development opportunities under the previous government, the union said, but will now be given the tools and time to grow teaching careers.
Teachers Federation President Henry Rajendra says working conditions were "very, very difficult". (James Gourley/AAP PHOTOS)
The multi-year deal follows a major one-off pay increase for teachers that was agreed in September 2023.
It made many the nation's best-paid for their cohort and included a 12 per cent boost in starting salaries to $85,000 a year.
Education Minister Prue Car said vacancies in public schools had fallen significantly since the initial deal was struck, while the government was also trying to improve working conditions to retain existing staff.
"The things we've been able to collaborate on, we're seeing results on," she said.
Salaries for teachers at the top of the pay scale went from $113,042 a year to $122,100 under the previously agreed increase.