Gowling, 24, has signed a two-year contract with the Cumbrians, having previously looked set to join their League One rivals Walsall.
Carlisle boss John Ward told the club's official website: "Josh has been playing in the centre of the defence for Bournemouth and he has been playing consistently well for them.
"He has the flexibility to be able to play at full-back if we need it and that's good for us to have in the squad. He is a very good player who is only going to get better.
"Having spoken to Josh I got the feeling, almost immediately, that he wants to come up here and compete. He knows that it will be tough for him to break into the side."