Ex-England second-row Tom Palmer will play for Treviso next term.
Palmer, who has just finished his sole season with Gloucester, has won 42 caps for England and Gloucester boss David Humpheys is sorry to see him leave Kingsholm.
"When you look back on all the big performances this season, and every game TP has played, he has brought the commitment and work-rate of a senior international player," Humphreys said in the Gloucester Citizen. "TP and Tom Savage have been two of our highest performers on a weekly basis. He has brought that and big hits every week and that's why he will be sorely missed.
"His impact off the pitch was also invaluable. He brought the playing experience he has from top environments across Europe and showed the young players how to prepare and recover from matches. We're very sorry to see him go.
"We were desperately trying to find a way to keep him but ran out of time. I'm sure he will be a great signing for Treviso and we all wish him the very best for the future."