Galchenyuk has also previously played for the Arizona Coyotes, Pittsburgh Penguins, Minnesota Wild, Ottawa Senators, Toronto Maple Leafs, and Colorado Avalanche.

In his first season with the Sting, Galchenyuk recorded 31 goals and 52 assists for 83 total points, which led to him being selected to the OHL 1st All-Rookie team alongside teammate Nail Yakupov.

[4] During the 2012–13 NHL lockout, he played for Sarnia in the OHL, where he served as captain of the team during his final season for the Sting[5] and where he dominated by recording 27 goals and 34 assists in 33 games.

On June 29, 2019, Galchenyuk was traded to the Pittsburgh Penguins along with Pierre-Olivier Joseph in exchange for Phil Kessel, Dane Birks, and a fourth-round pick in 2021.

[19] Galchenyuk returned to make 45 appearances with the Penguins, struggling to match his previous career offensive output in recording 5 goals and 17 points.

On February 10, 2020, Galchenyuk, prospect Calen Addison, and Pittsburgh's first round pick in the 2020 NHL entry draft were traded to the Minnesota Wild in exchange for Jason Zucker.

[20] On October 28, 2020, Galchenyuk signed as a free agent to join his fifth NHL club in the Ottawa Senators on a one-year, $1.05 million contract.

[23] On the following day, Galchenyuk was placed on waivers by the Hurricanes and upon clearing was assigned for the first time in his career to the AHL joining affiliate, the Chicago Wolves, on February 15, 2021.

[24] That same day, before he could join the Wolves, Galchenyuk was traded by the Hurricanes to the Toronto Maple Leafs in exchange for Yegor Korshkov and David Warsofsky.

[25] The Galchenyuk acquisition was initially seen as an insignificant depth move, and after the trade he originally played for the team's AHL affiliate, the Toronto Marlies.

[26] After putting up 8 points in 6 games, Galchenyuk was called up to the Maple Leafs, eventually making his debut on March 19 on a line alongside William Nylander and John Tavares.

On September 21, 2021, Galchenyuk was signed to a professional tryout (PTO) contract with the Coyotes, making his return to Arizona after being traded by the franchise in the 2019 off-season.

As a free agent at the conclusion of his contract with the Coyotes, Galchenyuk remained unsigned over the summer and for the second consecutive year accepted a PTO invitation to join the Colorado Avalanche's training camp on September 20, 2022.

[32][33] In recovering from his injury and remaining within the Avalanche organization, Galchenyuk was signed to a AHL contract to begin his 2022–23 season with affiliate, the Colorado Eagles, on November 10, 2022.

[43] With NHL interest ceased as a free agent, Galchenyuk opted to pursue his professional career abroad by agreeing to a two-year contract with SKA Saint Petersburg of the Kontinental Hockey League (KHL) on August 25, 2023.

Opting not to proceed with the second year of his contract with SKA, Galchenyuk was signed by fellow Russian club, Amur Khabarovsk on a one-year deal, on May 17, 2024.