The 23 year old, who has made 11 appearances for Wales, moves to the Welsh capital ahead of the beginning of the 2014/15 season to play for the Blues.
Tavis spoke to the club website about his decision and will leave Kingsholm with some fond memories of his season at the club.
"I've loved my time at Gloucester, there is no denying that but it's an exciting opportunity to move closer to home and open a new chapter in my rugby career with the Blues.
"Nigel and the coaches have taught me a lot and playing in the Aviva Premiership and in some big Heineken Cup games have been great experiences.
"Kingsholm is such a special place to play and I will miss that atmosphere, but I can reassure our great supporters that I will be giving my absolute all between now until the end of the season."
Nigel Davies, Director of Rugby for the Cherry and Whites wishes Tavis well:
"Tavis was a good signing for us in the summer and added real strength in depth to the squad. He suffered with quite a few injuries at the start of the season, which meant that he didn't have the platform to spring into the season.
"So he's been frustrated with that himself, and he also hasn't had as many opportunities as he would have liked. But I think he's enjoyed his time here and we've seen the best of Tavis in the past couple of games.
"He wants to go back to Wales, he's comfortable there, and push for national honours. He feels he's best placed to do that in Wales. But he's still got a part to play here at Gloucester and, when the time comes, we'll wish him all the best for the future."