Kelly posted the sweet picture on Instagram yesterday (22 May) for 'Throwback Thursday' and it shows the siblings sitting in the back of their parents' car.
Making sure Jack knows who's boss, Kelly has got a firm grip on his chops while also managing to pout at the camera. Once a diva, always a diva!
Alongside the photo, Jack said: "#TBT Had to share this TODDLER throwback of me and my baby brother! Love you @mrjacko xoxo…"
Writing on her website, kellyosbourne.com, she added: "Growing up Jack and I were inseparable…
"I'm so glad that now that we are past our awkward teenage years, we are like this again. I know I embarrass him when I say this, but I love my baby brother!"
And to think this is the same brother and sister who fought like cat and dog on The Osbournes!
Were you a fan of The Osbournes? Tell us below, as the best comment from across the website each week wins £50!