Opposition Leader Bill Shorten used social media on Thursday to announce the policy, which he said would ensure kids get the best quality education in the world.
"My shadow colleagues and I have been talking about the largest boost for school funding in Australia in two generations," he says in the video message.
Mr Shorten will commit Labor to fully funding the Gonski agreements it struck with state and territory governments in 2013.
The coalition government has only committed to funding the first four years of the six-year funding deals.
Previously, Mr Shorten refused to say whether Labor would fund the extra two years which contain the biggest increases.
The policy is expected to cost $4.5 billion over the 2018 and 2019 school years.
