The former Home And Away actor, who recently had a mass removed from his head after suffering a sudden migraine, revealed the news to fans on Instagram via a video.
"Hey guys, I've joined walk for brain cancer as an ambassador to help raise awareness and funds for this awful disease!" he announced.
"I would love for you to join me on the walk on the 5th of November In Sydney or join in on one of the many walks around Australia, If you'd like to donate to Team Johnny go to https://www.walk4braincancer.com.au/my-fundraising/donate/5854/team-johnny & make a donation, Thankyou so much & hope to see you out there walking with me! Xx @curebraincancer," he continued.
Since Ruffo's surgery, he spoke to NOVA' Fitzy and Wippa and revealed that in order to get rid of the remaining 5% of the tumour he is currently undergoing radiotherapy.
He will then start chemotherapy for six months, and although his doctors can't give a definitive answer, they are hopeful for a positive outcome.
This article originally appeared on WHO.