Johnny was first diagnosed with brain cancer in 2017 after suffering headaches and often credits his girlfriend for saving his life after she took him to hospital.
He went through multiple rounds of chemotherapy before finally taking to Instagram in August 2019 to announce that he had "beaten" the life-threatening disease and shared his relief.
The actor has previously opened up about how tough it was to hear the diagnosis and later fight the disease.
“It's pretty heavy hitting from the get-go so it's not something that doesn't really sink in straight away. As soon as you hear the news it's like... sh*t,” he revealed of the ordeal in 2018.
“It's been pretty full on. But I think as you go on, you kind of find ways to deal with it a bit more and just develop coping mechanisms.”
When it comes to the tough moments in his battle against the disease, the X Factor star explained that “it ebbs and flows.”
“During chemo's the worst I suppose - you're vomiting and feeling like absolute crap and nauseous,” he shared.
“I guess you've just got to take the good with the bad. The good days you enjoy a lot more because you don't know when they're going to be and how far apart they are. All in all, I've been fairly positive throughout the whole ordeal.”
Speaking to Now To Love last December, Johnny revealed how anxious he gets as he attends regular check-ups.
"I always expect the worst. I don't know why. I just expect the worst and when they go, 'Oh, you're still fine mate', I go '[pauses]… thank you.'"
Explaining, he added: "It's hard not to because I don't want to get my hopes up and then they go, 'Oh we've seen this, you might have to do some more chemo.' It's probably not a bad thing. It just makes me quite anxious leading up to it. It's not fun."
During his health battle Johnny has often praised his girlfriend Tahnee for being by his side every step of the way.
"Without her I may not be here," he told Now To Love last month.
"She was the one who made me get in the car when it first happened. And she's encouraging me to do things. She keeps me active, getting me to go for runs and swims."