The 26-year-old was released as a free agent last Friday after failing to make a single league start in his 12 months at The Hawthorns having checked in from Juventus. He still had two years left to run on the contract.
He made just seven appearances for the Baggies in total, six as a substitute in the Championship and one as a starter in the EFL Cup first round defeat at Fleetwood.
Frabotta has joined Cesena in Italy. The club, based in the Emilia-Romagna region, play in the second tier of Italian football.
They finished seventh in Serie B last season. Cesena are a phoenix club having formed in 2018 following the bankruptcy of the old AC Cesena and won promotion to Serie B in 2023/24.
Frabotta has signed a one-year contract with the option of a further 12 months. He previously had Serie B loans with Frosinone, Bari and Cosenza from former club Juventus.