He spent two years with the UMass Lowell River Hawks, where he received the inaugural Mike Richter Award as the top goaltender in college hockey.

Hellebuyck started his professional career during 2014–15 season with the Jets' American Hockey League affiliate, the St. John's IceCaps.

[7] Hellebuyck chose to forgo his final two years of college eligibility by signing a three-year, entry-level contract with the Winnipeg Jets on April 5, 2014.

He was immediately assigned to the St. John's IceCaps, the Jets' American Hockey League (AHL) affiliate, for the remainder of the season but did not play a game.

[10] Hellebuyck started the season sharing the net with Peter Budaj but quickly became the IceCaps starter by mid-November.

[11] Through his first six starts, Hellebuyck earned his first professional shutout, had a .955 save percentage, and tied for eighth in the league in goals against average (GAA).

[13] Although the IceCaps continued to struggle, with an Eastern Conference-worst goals against record,[14] Hellebuyck tied for fourth among all goalies in wins, and third among league rookies in save percentage.

"[16] Hellebuyck recorded his fourth shutout of the season on February 7, 2015, against the Portland Pirates,[17] and his fifth the following night against the Hartford Wolf Pack.

[27] Hellebuyck attended the Winnipeg Jets training camp ahead of the 2016–17 season and made the team's opening night roster alongside Michael Hutchinson.

[31] Hellebuyck finished his rookie season with a 26–19–4 record through 56 games and a 2.89 goals-against average, .907 save percentage, and four shutouts.

[32] After making the opening night roster after the Jets' 2017–18 development camp, Hellebuyck played the majority of the season alongside Steve Mason.

[34] Hellebuyck excelled in his role as starter, recording 23 wins through 35 games including three shut outs, a .923 save percentage, and 2.36 GAA.

[39] Hellebuyck also set a franchise record with nine shutouts, a .924 save percentage,[40] and nine straight wins to end the regular season.

[41] As a result of his successful play, Hellebuyck was named a Vezina Trophy runner-up as the league's top goaltender behind Pekka Rinne.

[44] Over five games against the Wild, Hellebuyck recorded two shutouts to lead the Jets to their first playoff series win in franchise history.

[46] While the series was pushed to seven games, Hellebuyck made 36 saves in the 5–1 win to lead the Jets to the Western Conference final.

[49] However, head coach Paul Maurice continued to rely on both Hellebuyck and Brossoit, saying: "We've got a luxury here....We've got two goaltenders that we really feel confident in playing.

[54] After earning his 14th career NHL shutout on March 23, Hellebuyck and the Jets qualified for the 2019 Stanley Cup playoffs.

[59] On January 14, 2020, Hellebuyck recorded his fourth shutout of the season to end the Jets' six-game losing streak.

[61] At the time of the pause, Hellebuyck ranked second in the NHL in wins with 31, first in shutouts, and seventh in save percentage among goalies who played at least 20 games.

[62] His efforts helped the Jets maintain a 37–28–6 record and advance to the 2020 Stanley Cup Qualifiers once the NHL resumed play.

[64] On September 21, before Game 2 of the Stanley Cup Finals, Hellebuyck was named the winner of the Vezina Trophy, becoming the first goalie in Winnipeg Jets/Atlanta Thrashers history to win the award.

[66] On February 4, Hellebuyck won his 153rd NHL game as the Jets beat the Calgary Flames 4–1, breaking the Jets/Thrashers franchise record for wins by a goaltender.

[68] Through the first week of April, Hellebuyck won three consecutive games, including one shutout, and led the NHL in shots against, saves, and minutes played.

[75] Hellebuyck was voted by fans to play in the 2023 NHL All-Star Game alongside Jets defenceman Josh Morrissey.

[79] The Jets allowed a league-low 199 goals in 82 games, and as a result Hellebuyck received the William M. Jennings Trophy.

[89] In 2023, Hellebuyck co-authored two children's books about mental health with Thom Van Dycke titled "Bucky Beats the Blues" and "Is Something Wrong With Weasel?