The Hawaiian beat six-time world champion Stephanie Gilmore and world number one Tyler Wright. She tweeted: "Beyond stoked to finish 3rd... as the wildcard! LOVED competing & looking forward to more adventures."
The story of how Hamilton returned to surfing after losing her arm in shark attack aged 13 inspired the film Soul Surfer.
The biopic tells the story of how Hamilton's Christian faith aided her recovery.
Writing on her website about her Christian faith Hamilton said: "At a young age I was introduced to what Jesus Christ has done for all of mankind. Through his death and resurrection on the cross, He provides the forgiveness of our sins and eternal life. This gives me hope in the future that I have as a Christian.
"As rough times come my way, like when I lost my arm to the shark, and as life throws challenging curve balls, I take joy and am grounded in God's promises found in His Word, the Bible. I still hold fast to his truths today."
Hamilton says she is in a "unique position" to "encourage young girls to chase their dreams".
"Even after losing my arm I'm still doing everything I hoped I could do. I'm a reminder for young girls that you can do it if you set your mind to it."