Watt, a 6'10" forward-center from Desert Edge High School in Goodyear, Arizona, came to Buffalo to play for coach Reggie Witherspoon. After cracking the starting lineup as a freshman in 2008–09, Watt established himself as one of the top defensive players in the MAC, earning the nickname sWatt. As a sophomore, Watt battled Guillain–Barré syndrome, which limited his effectiveness. His role was largely as a rebounder and defensive stopper his first three years. As a junior, he averaged 8.0 points, 5.3 rebounds and 2.2 blocked shots per game. As a senior, Watt continued his strong defensive play, but also nearly doubled his scoring output. He averaged 16.3 points, 7.3 rebounds, 2.2 assists and 2.2 blocks per game. He led the Bulls to a 12-4 MAC record and was named conference player of the year and an AP honorable mention All-American. For his career, Watt scored 1,061 points, 565 rebounds and 195 blocks. At the end of his career, Watt was invited to play in the Reese's College All-Star Game at the 2012 Final Four.
In July 2014, Watt joined the Golden State Warriors for the 2014 NBA Summer League. On September 2, 2014, he signed with the Warriors. However, he was later waived by the Warriors on October 24, 2014. On November 3, 2014, he was acquired by the Santa Cruz Warriors as an affiliate player. On December 22, 2014, he left Santa Cruz and signed with his former team Ironi Nes Ziona of Israel for the rest of the season.
In August 2016, Watt signed with JuveCaserta of the top Italian league, Serie A. Averaged 14.9 points, 9.0 rebounds was named team MVP.
2017–18 season
In August 2017 signed a 2 year deal with Reyer Venezia. On 2 May 2018, Watt won the FIBA Europe Cup with Reyer Venezia. Averaged 11.5 points, 4.5 Rebounds. Finished 3rd place in Italian League.
2018-19 season
In June 2019 won the Italian league championship with Reyer Venezia. Finalist for Italian league MVP. Averaged 15.3 points per game and 5.5 rebounds per game, Lead the league with 70.1 FG% named all Italian league second team. Has played in 126 straight games with Reyer Venezia. 2 Time round league MVP including a 27 point 9 rebound vs Avellino.
2019-20 season
Won 2020 final eight Italian Cup with Reyer Venezia. Selected First Team all Final Eight Cup.Eurocup regular season round 6 MVP v Partizan NIS With 27 points 11/12 FG 37 value. Reyer made quarterfinals of Eurocup but was suspended indefinitely due to covid-19. He averaged 12.9 points per game and 5.1 rpg With a value of 14.6 and named euro basket all eurocup honorable mention. In Italian Lega Basket he averaged 14.5 points per game 7.4 rebounds per game with 18.4 value. He was named Lega Basket Serie A First Team All Defensive Center and Lega Basket Serie A First Team center.
2020–21 season
On June 22, 2020, Watt signed a multi-year contract extension with Reyer Venezia.