Balotelli, born in Palermo to Ghanaian immigrants, has signed a two-year contract with his new club after leaving Turkish club Adana Demirspor.
FC Sion becomes Balotelli’s 11th club in his career.
The move comes just days after he nearly clashed with Adana Demirspor manager Vincenzo Montella.
The forward signed a three-year contract with Adana Demirspor in July 2021 and has enjoyed something of a comeback in Turkey since leaving Monza.
However, after only 13 months at the club, he has left after a heated argument with his former manager Montella.
Last season, he scored 19 goals for the Turkish club, his second-highest total in a season after the 24 he scored for Nice in 2017-18.
The 32-year-old began his career at Lumezzane in Italy before joining Man City from Inter Milan in 2007.
Before joining his current club in Switzerland, he played for AC Milan, Liverpool, Nice, Marseille, Brescia, Monza, and Adana Demirspor.