DeBrincat signed with the Erie Otters of the Ontario Hockey League as a free agent on April 29, 2014, and joined the club for the 2014–15 season. He appeared in his first career OHL game on September 24, 2014, and scored his first goal against Nikita Serebryakov of the Saginaw Spirit in a 7–1 win. On November 7, DeBrincat scored his first career hat trick in a 5–2 win over the Sarnia Sting. In his final regular season game on March 22, DeBrincat scored a goal and added five assists for a six-point game as the Otters defeated the Niagara IceDogs 8–7. DeBrincat finished the season with 51 goals and 104 points in 68 games, and led all OHL rookies in goals, assists and points. In the post-season, he had nine goals and 16 points in 20 games, as the Otters lost to the Oshawa Generals in the J. Ross Robertson Cup finals. DeBrincat won the Emms Family Award, which is awarded to the OHL Rookie of the Year, and was named the CHL Rookie of the Year. DeBrincat also was named to the OHL First All-Rookie Team, and the OHL Second All-Star Team. In 2015 he was named the OHL Player of the Month for March after he tallied 16 goals, seven assists and 23 points in 12 games. He also became the first Otters player to record back-to-back 50-goal seasons and record five hat-tricks in a season. In the 2016–17 season, DeBrincat led the OHL with a high of 65 goals along with 62 assists and a plus-minus rating of plus-60. In May 2017, he was named the 2016–17 recipient of the Red Tilson Trophy which is awarded to the most outstanding player in the OHL.
Professional
After three seasons with the Otters, DeBrincat made the Blackhawks roster out of training camp at the start of the 2017–18 season. He made his NHL debut on October 5, 2017, in a 10–1 victory over the Pittsburgh Penguins. On October 10, DeBrincat scored his first NHL goal in a game against the Montreal Canadiens on goaltender Carey Price. On November 27, DeBrincat recorded his first NHL hat trick against the Anaheim Ducks making him the second youngest Blackhawks player to score a hat trick, just behind Jeremy Roenick by four days. He scored his second hat trick of the season on January 25, 2018, against the Detroit Red Wings to cinch a 5–1 win in his home state of Michigan. By doing so, he became the youngest Blackhawks player to record two regular season hat tricks in one season, as well as the first rookie to do so since Steve Larmer in the 1982–83 NHL season. DeBrincat recorded his third career hat trick on March 18, 2018, against the St. Louis Blues. With his third hat trick in his rookie season, DeBrincat set a new Blackhawks rookie record and tied Tony Granato for most hat tricks by a U.S born rookie in a season. The following day, DeBrincat became the youngest Blackhawks player to be awarded the Blackhawks Player of the Year Award. He concluded his debut season with 52 points, including a team-high 28 goals. DeBrincat surpassed his career high in goals, assists, and points during the 2018–19 season. He primarily skated on the Blackhawks' second line alongside with his longtime friend and former Otters' teammate, Dylan Strome, whom the Blackhawks acquired in November. On February 18, 2019, DeBrincat recorded his fourth career hat trick and two assists in a 8–7 win against the Ottawa Senators. This was the first five point night in his career. On October 3, DeBrincat signed a three year contract extension with the Blackhawks.
International play
DeBrincat was named to Team USA in the 2016 IIHF World Junior Championships in Helsinki, Finland. He was injured in a game against Sweden but recovered quick enough to net a vital goal against the Czech Republic in the quarterfinals. He ended the tournament with 1 goal in 5 games to help Team USA clinch Bronze. After the conclusion of his rookie season with the Blackhawks, DeBrincat was named to the Team USA roster to compete at the 2018 IIHF World Championship. He contributed with 9 point in 10 games to help the United States claim the Bronze Medal in Denmark. DeBrincat returned to the World Championship the following year, as he was named to Team USA roster to compete at the 2019 IIHF World Championship, held in Bratislava and Kosice, Slovakia.
Personal life
DeBrincat attended Harrison High School in Farmington Hills, Michigan for one season before transferring to Lake Forest Academy, a school known for their athletics. He has an older brother named Andrew who played hockey for Lake Forest Academy for two seasons before graduating in 2012. His father, David is Maltese and his mother, Tracey is Canadian.