Byrne is yet to appear for the Spurs first team, but spent three months at Brentford last season.
Cherries boss Lee Bradbury told BBC Radio Solent: "He comes with a good background, and we're delighted."
He added: "He's highly-rated at Spurs, and there were a couple of other League One clubs after him, but we managed to get in first and it's a great signing for us."
"He's very mobile, and he'll fit into our squad nicely."
Source: BBC Sport
Source: BBC Sport