When it comes to his personal life, Jason keeps a relatively low profile, and rarely posts photos with his current rumoured-girlfriend Jules Hawkins.
They sent fans into a frenzy back in 2016 when they posted a photo of them kissing in Ibiza.
Later that year they were spotted arm-in-arm at the Red Bull Air Race World Championships at Ascot Racecourse in England.
Jason met Jules after his break-up from ex-wife Lucy Culkin, who he married in September 2011.
The pair tied the knot in a lavish ceremony in the harbour town of Salcombe in Devon, in England's southwest.
Jason and Lucy welcomed their daughter Honor in June 2012.
But unfortunately their marriage didn't go the distance, after his deteriorating mental health and PTSD from his time in service took its toll on their relationship.
"I've got two marriages that have gone down the pan - I like to attribute it to the military life but then I look at the common denominator which is me," he has previously said.
Jason was married once before Lucy, and has another daughter with his first wife, though not a lot is known about them.
In 2012, the 44-year-old's life took a turn for the worse when he was diagnosed with "PTSD and chronic burn-out," which resulted in him leaving the military altogether.
Jason, who has become a pioneer for soldiers' mental health, wasn't always as candid about his own struggles.
"I found it very difficult to admit that to myself. What I started to do was lie to myself about what was going on and put it down to other things that were going on in my life," he told Lad Bible in 2019.
"It was getting to the point where I had to do something, and it was like the last resort, but I never wanted to speak to anyone. I just wanted to push it under the carpet and crack on - the old stiff upper lip.
Jason credits getting professional help with saving his life, saying he was spurred on by the thought of staying strong for his mother and daughters.
"I would have probably stayed in my job and I'd have got sicker, mentally, because I'd have continued doing something without addressing it," he said.
"I'd have either been completely reckless and died being away, just throwing caution to the wind because that's one thing I think I might have done, or I'd have gone into a massive fit of depression at some point and probably killed myself."
Despite witnessing his friends being killed during his 20-year service, and enduring the fallout of his marriage, Jason said he didn't actually hit rock bottom until he left the military.
"It wasn't until I left and lost my identity, that was the lowest point I remember. Leaving and everything else falling apart afterwards, that was the low point - that completely overshadows all the others," he said.
"Also I was like a big non-believer in PTSD and mental health issues in soldiers because I'd hear stories of people suffering from experiencing combat. I'd done years prior to that and I was fine, so I'd be like 'what you going on about - I've been in some proper scrapes and I'm still alright'."
Jason said that just 12 months later he ate a "big slice of humble pie" when realising he needed help to work through his mental health issues.
The father-of-two shot to international fame after appearing on the highly-successful SAS: Who Dares Wins in the UK.
The new season of SAS Australia premieres next month, where 18 Aussie celebrities will take on one of the toughest tests of their lives.
The series will also star Ironman Jett Kenny, celebrity chef Manu Feildel, volleyball champion Kerri Pottharst, singer Pete Murray and tennis star Mark Philippoussis.
Jason will be joined by fellow directing staff Ant Middleton, Mark “Billy” Billingham and Ollie Ollerton to instruct the recruits as they face a series of physical and psychological tests from the real SAS selection process.