Skoolbo was founded in 2011 and focuses on game-based learning for children in the areas of literacy, numeracy, health and fitness. More than 50 per cent of primary schools in Australia and New Zealand are registered on Skoolbo's platform, which operates across web, mobile, TV and social media.

It is also expanding into the US and Britain.

A Fairfax spokesman declined to reveal the percentage of its stake or how much it is worth.

Fairfax Digital Ventures director Guy Reypert said: "This investment gives Fairfax exposure to the fast-growing online education sector, which allows high quality learning resources to be delivered at scale and low cost.

"We look forward to working with Shane (Hill), a proven entrepreneur in online education, to accelerate the growth of Skoolbo and we see numerous ways that our businesses can work together as partners."

Fairfax Media is the owner of The Age, The Sydney Morning Herald and The Australian Financial Review.