Hundreds of preschools across NSW have opened their doors to the first cohort of subsidised three year olds this week, thanks to a historic investment from the NSW Government to ensure every child has access to two years of quality early childhood education.

Melinda Pavey MP, the Member for Oxley,  said for the first time ever preschool subsidies have been extended to include all three and four-year-olds, saving families an average of $825 a year.

"This investment provides better opportunities for children starting their schooling," Mrs Pavey said.

"This is also another way that the NSW Government is helping to reduce family's costs-of-living.

"I look forward to seeing children starting school more equipped with the skills to succeed, thanks to this historic investment."

Minister for Early Childhood Education, Sarah Mitchell, said universal access to two years of preschool education provides extensive benefits.

"Children who have two years of quality early childhood education achieve better results throughout primary and high school.

"In June last year when the Budget was delivered, NSW was the only state in Australia in the financial position to offer three-year-old preschool subsidies, and I am proud that other states have since followed suit and modelled their policy off ours."

The NSW Government's Start Strong program was introduced in 2016 and has already seen significant success for children attending preschool for 600 hours in the year before school, a reduction in average daily fees by 25 per cent and an increase in enrolments by 40 per cent.