Jason - who dated Lauren Conrad - is playing baseball in the childhood snap and looks very serious as he prepares to throw the ball to the batsman.
Now aged 27, Jason posted the photograph on Twitter, saying: "16 yrs ago..... :)"
Jason first found fame in 2005, after landing a role in the second series of MTV reality series Laguna Beach: The Real OC.
After having a brief relationship with Lauren, which ended when he kissed classmate Jessica Smith, Jason popped up in spin-off show The Hills.
Lauren decided to give Jason another chance and earned herself the title 'The Girl Who Didn't Go To Paris', after turning down a trip to France with Teen Vogue so she could spend the summer with him in California.
The couple soon split, due to Jason's spiralling issue with alcohol, and, in 2010, he entered TV show Celebrity Rehab with Dr Drew. He is now sober.
In February, Jason wrote in a blog post for Huff Post: "A few years ago, I would host parties at my house in LA where there would be 50 -100 people raging out of control.
"While everyone thought I was enjoying the party as much as they were, little did they know I was secretly going into the master bathroom and snorting as much coke and drinking as much alcohol as I could."
He added: [I hope] that I can continue to educate more people about how important it is to not only get into treatment if necessary, but also to continually stay connected to prevent relapse."
Jason is now happily married to model Ashley Slack.
Where are they now: Laguna Beach: The Real OC