This has got to be one of the cutest celebrity families out there!

OK! GALLERY: NICOLE RICHIE AND JOEL MADDEN HANG AT THE VOICE AUSTRALIA PARTY IN SYDNEY

Nicole Richie and Joel Madden took their kids Harlow and Sparrow for a family day out at the zoo in Sydney, Australia.

Young Sparrow and Harlow just looked at every animal they saw in absolute awe. And we can't get over their curls!

Their daddy even Tweeted about their fun-filled day: "Thanks Toronga Zoo for having us today with the kids. They are still buzzing from it. Can't get enough. We'll be back fo sho."

OK! GALLERY: NICOLE RICHIE PROMOTES FASHION STAR AT NBC UNIVERSAL PRESS DAY

Joel is in Australia as he is one of the judges on The Voice: Australia.