The 22-year-old fly-half will be returning to Welsh rugby after spending the last four years at Bristol.
A former pupil of Ysgol Gyfun Gymraeg Glantaf in Cardiff, Lloyd was part of the Cardiff Blues pathway before moving to Clifton College where he linked up with the Bears.
He became Bristol’s youngest-ever player in the English Premiership when, at the age of 18, he made a try-scoring appearance as a replacement in the West Country derby against Bath.
Lloyd was capped at U18s and U20s level and graduated to Wales senior honours in 2020, making two appearances off the bench during the Autumn Nations campaign that was played at Parc y Scarlets. He has made 78 competitive appearances for Bristol.
Scarlets head coach Dwayne Peel said: “Ioan is a high-quality player with a huge amount of talent, a ball player with the ability to break the line and take on defences. He is a player who we feel will fit well with the way we look to play here and we’re looking forward to welcoming him in the summer. He is a young man and we’re looking forward to seeing him grow in a Scarlets shirt.”
Lloyd said: “It has been a very hard decision to leave Bristol. I’ve had a fantastic four years at the club and I leave having made many good friends. However, having sat down a few times with Dwayne, I feel a move to the Scarlets is a good rugby one for me and will help me further develop as a player. I feel the Scarlets’ game-plan will suit my style of play and I’m excited to get stuck in next season.
“But for now, my focus is on working hard to help Bristol finish the season strongly.”
Lloyd’s signing comes on the back of Wales international hooker Ryan Elias committing himself to the Scarlets with a new deal. Further contract announcements will be made this week.