Tonut came through the youth ranks of Monfalcone and
Pallacanestro Trieste, before transferring again to Monfalcone, where he made his debut for the club’s men’s team in the amateur Italian third division during the 2010–11 campaign. Tonut later returned to
Pallacanestro Trieste where he played for the first time in the
Serie A2 during the 2012-13 season. During the next two seasons, he was ranked as the fourth-best scorer in the league and the best Italian player of Serie A2 with averaging 19.2 points per game. Tonut then joined
Reyer Venezia of the
professional Italian top-flight level league
LBA in July 2015. In his first season with the team, he saw the court in 34 games in the LBA, scoring 2.8 points per outing. In the 2015–16 season, he marked his debut on the European club stage, participating in the
European second tier EuroCup competition with Venezia. In 2017 and 2019, Tonut won the LBA championship with Reyer. In the 2020–21 season, Tonut won the
LBA Most Valuable Player Award after averaging 15.6 points, 3.9 rebounds and 2.9 assists. On 25 June 2022, Tonut signed with
Olimpia Milano of the Italian
Lega Basket Serie A (LBA) and the
EuroLeague. On 28 June 2024, he renewed his contract with the Italian powerhouse. ==International career==