[6] Tkachuk spent his formative years in NHL hockey rinks, watching his father practice from the players' bench.

As an infant in Scottsdale, Tkachuk's mother would drop him off at the Phoenix Coyotes' former arena, the Ice Den, during his father's practice days, where the team's equipment managers would take on babysitting duties while she ran errands.

[12] During this time, Tkachuk played minor ice hockey with a youth affiliate of the St. Louis Blues, where he was teammates with fellow St. Louis-area players Clayton Keller, Logan Brown and Luke Kunin.

[14] Tkachuk left St. Louis after the ninth grade to join the USA Hockey National Team Development Program in Ann Arbor, Michigan.

[15] Tkachuk was drafted by the London Knights in the fourth round, 64th overall, of the 2013 Ontario Hockey League (OHL) Priority Selection.

[20] During his time in Ann Arbor, Tkachuk played on a line with Auston Matthews and Jack Roslovic, and lived part-time with the family of teammate Christian Fischer.

[18] Before the 2015-16 season, Tkachuk opted to join the London Knights roster, forfeiting his NCAA eligibility and de-committing from the University of Notre Dame.

[28] Tkachuk became the second youngest teenager in Flames history to reach 100 games, the first being Dan Quinn in 1985, when he played against the Arizona Coyotes on November 30.

[34] After being absent from the Flames' training camp due to an unsigned contract, Tkachuk signed a three-year, $21 million extension on September 25, 2019.

The trio formed one of the most dominant forward lines in the NHL, and all three members hit numerous personal and collective milestones throughout the season.

[44] Tkachuk's own future with the team had been subject to speculation for some time, with many believing he intended to leave the Flames when he reached unrestricted free agency.

[45] Days after news of Gaudreau's departure, the Flames announced that they had filed for club arbitration on Tkachuk's next contract, having heretofore failed to come to terms on an extension.

This was widely interpreted as being a preliminary measure in a move to trade him to another team, and thereby avoid losing Tkachuk in free agency for no compensation.

[51] In recognition of his achievements, Tkachuk was named a finalist for the Hart Memorial Trophy, awarded to the league's most valuable player.

[citation needed] On January 9, 2024, against the St. Louis Blues, Tkachuk scored his fifth hat-trick and led the Panthers to their eighth straight win.

[55] He also competed at the 2015 IIHF World U18 Championships, where in seven games he registered ten assists (tops in the tournament), leading the U.S. under-18 team to a gold medal win.