The 54-times capped international joins from Zebre and will link up with this friend and fellow country man Andrea Masi at Wasps.
Masi and Festuccia grew up together in the city of L’Aquila and played there together before becoming team mates again at Racing Metro, where the hooker enjoyed four seasons.
In 2011, Festuccia returned to Italy to join Aironi before becoming a Zebre player.
The hooker has represented his country at two World Cups and will add important experience to the front row, where he will compete with Tom Lindsay and Neil Cochrane for the number 2 shirt.
London Wasps Director of Rugby Dai Young said: “We needed to add another hooker to the squad because there is no way we could go an entire season with just two players in an important position like that. Nathan Morris has gone on loan at London Welsh because we felt as a young hooker that that was better for his development, and so it’s a great bonus to bring in Carlo who has such strong experience. He’ll be training with the squad immediately.”
Festuccia added: “I am delighted to join Wasps and test myself in a new environment. I have played in the Pro12 and the Top 14 and always wanted to compete in the English Premiership, so this is an exciting move for me. I played for one of the oldest and best known clubs in France when I was at Racing Metro so to come to England and play for one of the oldest and best known clubs in England will be a fantastic experience.”