Head teachers and assistant principals in the average school will be expected to teach four days a week, while deputy principals will be asked to work two-and-a-half days under the policy.
Up to 2500 executive teachers, two-thirds of whom were not leading timetabled classes, will be expected to teach one day a week.
Salaries for the roles range from $140,500 per year to $164,000 after an eight per cent pay rise that kicked in from early October.
The changes could lead to the equivalent of more than 500 full-time teaching roles being added to state school rosters, the government said.
Prue Car believes the staffing changes will lead to better student outcomes. (Dan Himbrechts/AAP PHOTOS)
Education Minister Prue Car said it was vital for students that leading teachers took more classes at a time when 10,000 lessons a day were being merged or cancelled in the state's public schools due to staff shortages.
"We're confident that refining executive teaching positions - which were always a mixed role - and relieving them of administrative tasks will lead to better student outcomes through more teaching time across the state," she said on Friday.
Teachers have complained that increasing administrative burdens have been stymieing their abilities to properly lead classes while adding to unsustainable workloads.
Skilled administrative and support staff would be asked to take on some of the senior leaders' work in order to free them up for classes, the government said.
A NSW Department of Education review recommended a freeze on the appointment of extra teachers to executive roles remain in place until at least mid-next year.
There were nearly 2250 teaching roles vacant across the state's public schools as of late September.