The 35-year-old was available on a free transfer following his release by Reading.
Manager Eddie Howe has said that Harte's experience will be an asset to the Championship side.
"I am delighted to get someone with Ian's experience and technical quality. We are looking forward to working with him and I am sure he will be a welcome addition to the squad," he told the Bournemouth Echo.
"He impressed me when I used to watch him for Leeds. He is an excellent crosser and passer of the ball and his set-piece delivery is an added bonus.
"He has got a lot of the qualities we look for in a player. He has played in the Premier League and he will help our young squad. It was important we filled the position with someone who knows the game."
Harte played 16 times in the Premier League for Reading last season.