Co-star Alana Lister was first to wish Belinda a happy birthday.
"Aww I wish we celebrated together girl xxxx ❤️❤️❤️❤️," she commented on the post.
Fans also couldn't get enough of the former reality star's matching set.
"This outfit is everything 😍😍," gushed one.
"Leo ! ♌️ That explains the dramatic red mane and colour fashion creativity 🌈 Happy Birthday gorgeous 🎉🥳🎉," exclaimed another.
Belinda also shared a cute video of herself eating some birthday cake with some gal pals to her Instagram Stories.
One person who didn't publicly share a birthday message was Belinda's ex, Patrick Dwyer.
The couple, who went on to pursue a relationship after the show, called it quits in July via a joint statement.
"We got along really well and we had a wonderful relationship. But our perspectives on love and life goals ultimately didn’t align," Belinda told WHO.
She added: "It’s heartbreaking because I went on MAFS to find love and for a while, it looked like I had found it with Pat. But I grew so much from doing that show and learned so much about myself and what I really want in a relationship. I don’t have any regrets about my time on the show or my time with Pat, but now I’ve got to do what’s right for me."
Whilst she was known for her trademark brunette curls on MAFS, Belinda made the bold decision to go red shortly after the finale aired.
However, the new red look has nothing to do with her split with Patrick.
“Ha, no – I just love having fun with my look but now that I’ve gone full red there’s no way I’ll go back to brown,” she admitted to WHO when asked if her hair was inspired by the break up.
“I love my new red hair, I can’t believe I stuck with brown hair for so long."