He played a symbolic minute in LBA on 4 November 2011 before posting his first genuine first division stat sheet, missing his five shots for three rebounds and a steal, on 30 December.

[6] That season would also see his first participation in the playoffs, scoring 10.3 points and grabbing 3.3 rebounds per game as Virtus were swept by title holders Olimpia Milano.

[17] On 17 July 2022, Fontecchio signed a two-year contract with the National Basketball Association's (NBA) Utah Jazz.

[21] Fontecchio's career high came on 14 December 2023, against the Portland Trail Blazers, where he scored 24 points on 87% field goal percentage.

[22] On February 8, 2024, Fontecchio was traded to the Detroit Pistons in exchange for Kevin Knox II, a second round pick and the rights to Gabriele Procida.

He was the leading scorer in Italy's 92–82 win over Germany, scoring 20 points, grabbing 4 rebounds, dishing out 2 assists and stealing 3 balls.

[33] His father Daniele was a professional hurdler whilst his grandfather was also a basketball player, as is his older brother Luca who has played in the lower divisions after also coming through the youth ranks of Virtus.

Fontecchio moved to Bologna from his native Pescara at the age of 14, living in shared accommodation with other Virtus youth players.