Before turning professional, DiDomenico played major junior hockey in the Quebec Major Junior Hockey League for the Saint John Sea Dogs and the Drummondville Voltigeurs. Nearing the conclusion of the 2008–09 season with the Voltigeurs, DiDomenico was signed to a three-year entry-level contract with his draft team, the Toronto Maple Leafs on March 14, 2009.[1]
DiDomenico played two years within the Blackhawks' system, toiling between the AHL and East Coast Hockey League before opting to leave as a restricted free agent in the offseason to join Asiago HC of the Italian Serie A league in 2012. After two years with Asiago, DiDomenico left Italy but remained in Europe after agreeing to join Swiss club, SCL Tigers of the then National League B for their post-season campaign on February 12, 2012.
Helping the Tigers return to the top flight National League A, and in his fourth season with the Tigers in 2016–17, DiDomenico was approached with NHL interest. While leading the Tigers in scoring with 38 points in 48 games, DiDomenico was reluctantly released from his contract with SCL immediately after agreeing to a two-year deal to pursue his NHL ambitions with the Ottawa Senators under former junior coach Guy Boucher on February 27, 2017.[3] In signing with the Senators mid-season, DiDomenico was subject to waivers before joining the club. DiDomenico successfully cleared waivers on February 28, 2017, and joined the Senators. DiDomenico made his NHL debut on March 9, 2017 against the Arizona Coyotes.[4]
In the 2017–18 season, DiDomenico began the year with the Senators AHL affiliate, the Belleville Senators. After 4 games he was recalled and later scored his first NHL goal with Ottawa on October 27, 2017, against the New Jersey Devils with a late game-tying goal.[5] On November 23, 2017, after appearing in 12 games DiDomenico was waived by the Senators, and was then claimed by the Tampa Bay Lightning on November 24.[6][7] He was immediately assigned on a conditioning loan to the Lightning's AHL affiliate, the Syracuse Crunch. DiDomenico appeared in 3 games for the Crunch, scoring 1 goal.
On December 2, 2017, DiDomenico was claimed off waivers to return to the Senators organization.[8] On February 15, 2018, DiDomenico again left the Senators organization as he was traded to the Chicago Blackhawks in exchange for Ville Pokka.[9] He was assigned to the Blackhawks AHL affiliate, the Rockford IceHogs, where he quickly transitioned as the club's top offensive player by posting 23 points in 22 games to end the regular season.
After the season, DiDomenico as an impending free agent, opted to recommence his European career by returning to his former Swiss club, SCL Tigers, on an optional three-year contract on June 13, 2018.[10]
During the 2019–20 season, while in his sixth with the SCL Tigers, on January 15, 2020, DiDomenico agreed to a two-year contract commencing from the 2020–21 season to join fellow NL club, HC Fribourg-Gottéron.[11] After the regular season and before the relegation round, the Tigers immediately released DiDomenico.
On October 28, 2024, DiDomenico was part of a rare trade in European hockey, being sent from Fribourg-Gottéron to HC Ambrì-Piotta in exchange for Swedish left winger Jakob Lilja.[12]
