"Thanks to my friends and family who made it so special!"
She also posted a photo of her and boyfriend Cody Simpson, 22, sitting together at her birthday dinner.
"A silent birthday looks like this," she wrote, adding, "I have an App that helps me communicate but it really botches the comedic timing."
Miley and Cody were the subject of split rumours earlier this month when fans of the pair noticed they'd stopped posting photos of each other on social media.
However Cody was quick to dispel the rumours, clarifying that the pair are still very much an item.