Carey is staying as Ashton Gate after agreeing new contract.
Manager Derek McInnes said: "I am delighted Louis has now signed the deal. He certainly played his part at the end of last season with a strong run in the team.
It will be down to Louis how much he plays next season. I know he looks after his body and keeps himself fit. He's also a great person to have in and around the dressing room with so much knowledge and experience.
Louis added: "I am a Bristol boy and I love the club and the city. This deal is nothing to do with finances, I'm motivated by other things and I just want to carry on playing football for Bristol City."