He represented Italy at the 2016 UEFA European Under-17 Championship, they did not advance from the group stage.
He played in two group-stage games for Italy U-19 at the 2018 UEFA European Under-19 Championship, where Italy waOn 31 August 2018, Gabbia was loaned to Serie C club Lucchese on a season-long loan deal. On 16 September he made his Serie C debut in a 1–0 home defeat against Arezzo, he played the entire match. Eleven days later, on 27 September, he scored his first professional goal for Lucchese in the 47th minute of a 2–2 home draw against Carrarese. Gabbia ended his season-long loan to Lucchese with 30 appearances, all as a starter, he was replaced only 2 times, and he scored 1 goal.s the runner-up. He stayed on the bench in the semifinals and final.