Kyle was born and raised in Sault Ste. Marie, Ontario, Canada.
As a child, he played hockey, until concussions caused him to stop playing at the age of 14. His father was a Greyhounds intern and his grandfather, Walter Dubas, coached the Sault Ste. Marie Greyhounds from 1960 to 1967.
Kyle attended Brock University, graduating in Sport Management (BSM). While attending Brock, he worked as a scout for the Ontario Hockey League (OHL)'s Sault Ste. Marie Greyhounds.
In 2015, he was named the first recipient of Brock's Outstanding Young Alumni Award, for his accomplishments after graduation.
Brock University has credited Dubas's success early in his career with sharp increases in the popularity of their Sports Management program, with one professor noting, "We absolutely have seen, anecdotally, so many students who want to be Kyle Dubas when they graduate."
After graduation, Kyle offered to assist with Brock University's program as either an instructor or teaching assistant.
Kyle was the youngest agent ever certified by the National Hockey League Players Association. He worked with Uptown Sports Management and represented Kyle Clifford and Andrew Desjardins.
Kyle set up offices in Europe, however challenges with clients leaving for other agents resulted in Dubas looking for alternate careers in hockey.
Dubas was hired as the general manager of the Sault Ste. Marie Greyhounds of the Ontario Hockey League (OHL) in 2011. He attended his interview with a detailed plan to improve the team, which had struggled in recent years.
The Greyhounds initially were looking for an experienced candidate for the GM position, but Kyle's interview was so impressive, that he was the board's unanimous choice. During his tenure with the Greyhounds, this plan became known as "The Rising" (after the Bruce Springsteen song of the same name).
Kyle had been involved with the Greyhounds organization since he was a child, starting out as a stick boy and dressing room attendant when he was 11 years old. In this position, he hired Sheldon Keefe as head coach.
The combination of Keefe and Kyle resulted in significant on ice improvement for the Greyhounds, and during Kyle's last season as GM of the Greyhounds, they finished second overall in the OHL.
In 2014, Toronto Maple Leafs team president Brendan Shanahan reached out to Kyle about the possibility of joining the organization. Their initial meeting lasted nine hours. He was hired by Shanahan as an assistant general manager for the Maple Leafs in July 2014.
The Maple Leafs organization deflected concerns about his age at the time he was hired, with general manager Dave Nonis saying, "...Age was never a factor. It’s whether or not you can do the job, and it was clear to us quickly that he’s going to be good at it."
In January of 2015, Forbes named Kyle amongst its 30 Under 30 brightest young stars in the sport industry.
As an assistant GM for the club, Kyle played parts in many aspects of the organization, including personnel management and analytics, through the team's research and development group. He and Mark Hunter filled the role of interim general manager for the Maple Leafs in 2015, after Nonis was fired by the club.
After Shanahan hired Lou Lamoriello to serve as the team's general manager, Dubas and Hunter both took roles as assistant GM.
During his time as assistant GM for the Maple Leafs, Kyle also served as general manager of the Toronto Marlies, the Maple Leafs' American Hockey League (AHL) affiliate team. He was instrumental in organizing a system that developed players for the Maple Leafs team, while also being competitive in their own league.
Kyle hired former Greyhounds head coach Keefe to oversee the Marlies development. In 2018, the Marlies captured the Calder Cup as the AHL champions.
After the 2017–18 season, Shanahan decided not to renew Lamoriello's contract as GM, sticking to his original plan to have a fixed term on his time in the position before he transitioned into an advisory role. Kyle and his co-assistant GM Mark Hunter were considered top candidates for the position.
On May 11, 2018, Kyle was named as the 17th general manager in the club's history. Shortly after he was named GM, both Hunter and Lamoriello left the organization.
One of Kyle's first tasks as GM of the Maple Leafs was the 2018 NHL Entry Draft. He traded the team's first round selection at 25th overall to the St. Louis Blues in exchange for their pick at 29th overall and an additional draft pick at 76th overall.
The Leafs drafted Swedish defenceman Rasmus Sandin who played in the OHL for the Sault Ste. Marie Greyhounds, Dubas's former team.
During his first free agency period, Kyle made headlines by signing the top unrestricted free agent available, John Tavares to a seven-year contract.
Off the ice, Kyle hired Hayley Wickenheiser to serve as assistant director of player development. When hiring scouts, he introduced blinded reviews of players into the process. One of the highest scorers during this stage was Noelle Needham, who was hired as an amateur scout to cover the Midwest region of the United States.
Kyle has expressed a belief that increasing the diversity of the Maple Leafs staff will result in improved performance, saying, "Research shows the more diverse your organization, the better your decision-making and the better your operation in general. If you’re only hiring white males – and I’m saying that as a white male – you’re probably leaving a lot of good people, in terms of what where your organization can go and how it can think and how it can evolve and develop."
During the 2018-2019 season, Kyle received praise for the way he handled allegations that defenceman Morgan Rielly used a homophobic slur during a game. Rielly was cleared the following day after an investigation by the NHL.
At a press conference, the following day, he said, "It’s incumbent on us in management to build an environment if someone were gay, or were questioning their sexual orientation, that they don’t feel that they have to come in here and be somebody that they’re not."
Kyle's parents divorced when he was a child, his father was a police officer and his mother worked as an ambulance dispatcher. He has two sisters.
During his childhood, Kyle spent significant amounts of time with his grandparents growing up, and would often talk about hockey and baseball with his grandfather. He is married with a son.