The 21-year-old defender has joined the English Premier League club after two years with the Championship team.
English center-back Chris Mepham has joined AFC Bournemouth for a reported fee of £12 million, announced the English Premier League team in his official website.
Mepham started his career within the Chelsea youth system from 2008 to 2012.
He then joined the English Championship side Brentford were he spent four years in the young squad.
Mepham debuted professionally in 2016, where he played in 48 matches.
“It’s taken a while to get my signature on the dotted line but it’s been worth the wait,” Mepham told the club’s official website.
“There’s so much to like about this club, not least the manager. Eddie Howe is a fantastic manager and what he’s done here is remarkable, so to be working under him every day is a really exciting prospect.”
“I’m still young and have lots to learn and develop on my game but I can’t wait to get started, to meet everyone and to get out on the training pitch,” he added.
“Chris is a talented, young defender who has been on our radar for some time, so I am delighted he is finally our player,” Bournemouth manager Eddie Howe said.
“He has shown a huge amount of potential in his time at Brentford and while playing for Wales, and we believe this is the perfect environment to continue his development.
“Chris is a good defender and comfortable on the ball, and we believe he will be a great addition to the squad here,” Howe concluded.