The 20 year old was recalled from his loan spell at the Cherries this week due to an injury crisis at the Amex Stadium but has now agreed a three and a half year contract with the League One side.
Speaking to Bournemouth's official website the defender was in confident mood, "We are going places and I think we can make the play offs and I would be disappointed if we didn't."
"A lot of League One clubs could have given me first team football but I love it here. There's a great atmosphere and the club has so much potential I would be stupid not to sign," he added.
Cook has made eight appearances for the Cherries this season.
