The Fashion Police star joined Jack and Pearl at the famous theme park, with the highlight being meeting Jessie from Toy Story 2!
The trio visited Disneyland on Sunday (9 February) and Kelly has now shared several pictures of their trip.
In one, Kelly, Jack and Pearl are all huddled together for a cute selfie. Alongside it, Kelly told her Instagram followers: #SundayFunDay with my amazing brother and niece!"
She also uploaded a second snap, which show the exciting moment little Pearl met cowgirl Jessie.
Kelly said: "Watching Pearl meet #jessy yesterday at #Disneyland was one of the cutest things I have ever seen in my life! I love my niece soooo much!"
As teenagers, Kelly and Jack appeared alongside their parents - Sharon and Ozzy - on hit reality show The Osbournes and it's fair to say they didn't always see eye-to-eye.
However, like most siblings who squabbled when they were younger, now they're grown up they have a really close bond. Aww, you guys!