Barkov became the Florida Panthers' all-time leading scorer in a 5-2 win against the Detroit Red Wings at Little Caesars Arena on March 20, 2023. His second-period assist gave him 614 points (238 goals, 376 assists), passing Jonathan Huberdeau (613 points; 198 goals, 415 assists).

"He might be the most humble man I've ever met, and he's certainly the most humble elite player I've ever met," Florida coach Paul Maurice said after the game.

About 15 months later, Barkov the first Finland-born NHL captain to win the Stanley Cup after playing a key role in a 2-1 victory against the Edmonton Oilers in Game 7 to give the Panthers their first Cup championship in their history. He had five points (two goals, three assists) in seven games in the Final and 22 points (eight goals, 14 assists) in 24 playoff games and held Conn Smythe Trophy winner Connor McDavid to no points in Games 6 and 7. Leon Draisaitl, who had 31 points (10 goals, 21 assists) in the playoffs, had no shots and three attempts in 22:22 of ice time in Game 7 and three assists in the series.

Barkov and the Panthers repeated in 2025, defeating the Oilers 5-1 in Game 6, one day after he was named to Finland's preliminary roster for the Olympic Winter Games Milano Cortina 2026. He became the second player in NHL history to win the Stanley Cup and Frank J. Selke Trophy during the same season multiple times (2023-24), following Bob Gainey (1977-78 and 1978-79). He was the third player in 30 years to win multiple championships through his first seven seasons as captain of a franchise, joining Jonathan Toews of the Chicago Blackhawks (2010, '13 and '15) and Dustin Brown of the Los Angeles Kings (2012, '14).

The son of Alexander Barkov Sr., a former Russia national team member who played 10 years with Tappara of Liiga, the top pro league in Finland, Barkov Jr. has not only upheld the family reputation, he's enhanced it.

When Barkov, a center, made his Liiga debut with his father's former team Oct. 1, 2011 at 16 years, 29 days old, he became the youngest player in league history to score a point. It was the beginning of a trend.

At 16 years, four months, Barkov became the youngest player ever chosen to play for Finland in the IIHF World Junior Championship and youngest to score a goal when he scored in the 2012 quarterfinals against Slovakia.

The Panthers selected Barkov with the No. 2 pick in the 2013 NHL Draft. At 18 years, 31 days, he became the youngest player to score a goal in his NHL debut (Eddie Olczyk had been the youngest at 18 years, 56 days). Barkov beat Kari Lehtonen in Florida's 4-2 win against the Dallas Stars on Oct. 3, 2013.

Barkov had a breakout season in 2015-16. He signed a six-year contract Jan. 26, scored 59 points (28 goals, 31 assists) in 66 games and helped Florida win the Atlantic Division title. In 2017-18, he took another step toward becoming one of the elite centers in the NHL by scoring 78 points (27 goals, 51 assists) in 79 games. He played in the 2018 Honda NHL All-Star game, led the NHL with five shorthanded goals and was a finalist for the Lady Byng Memorial Trophy, awarded to player judged to have exhibited the best type of sportsmanship and gentlemanly conduct combined with a high standard of playing ability.

Barkov was named Panthers captain Sept. 17, 2018, scored his first NHL hat trick in a 4-3 overtime win against the Toronto Maple Leafs on Dec. 15 and became the first Panthers player with five assists in one game, a 6-2 win against the Minnesota Wild on March 8, 2019. He won the Lady Byng Trophy after getting four minor penalties during the season.

Barkov signed a six-year contract Oct. 8, 2021 and had another standout season, leading the Panthers with 26 goals and helping Florida earn a .705 points percentage (37-14-5). He also led Florida forwards in takeaways (39) and time on ice per game (20:56), and set personal bests in face-off winning percentage (54.9 percent) and shot attempts percentage (58.6 percent) and was voted the winner of the Selke Trophy as the best defensive forward in the NHL.

Barkov's upward trajectory continued during the 2021-22 regular season. He scored his 189th goal for the Panthers to pass former captain Olli Jokinen (188) for most in team history in a 7-3 loss at the New Jersey Devils on Nov. 9, 2021. He led Florida with 39 goals and four shorthanded goals in 67 games, and his 88 points were second behind Huberdeau's 115. His 47 road points (23-24-47) were the most in one season in Panthers history and he became their leader with 38 game-winning goals.

Barkov's assist on Sam Reinhart's goal 17 seconds into overtime of a 4-3 win against the Boston Bruins on Jan. 28, 2023, made him the ninth Finland-born player to score 600 points in the NHL, joining Jokinen (750 in 1,231 games), who had 419 of his 750 NHL points with Florida. He also joined Huberdeau as the only players in Panthers history to reach the milestone.

On Nov. 27, 2023, Barkov had three assists on the power play in a 5-0 win against the Ottawa Senators at Canadian Tire Centre to give him 192 points with the man-advantage, passing Huberdeau (190) for the most in Panthers history.

Barkov was voted winner of the 2024-25 Selke Trophy, the third time in four seasons he received the award. He was a key factor in helping the Panthers finish the season tied for first in the NHL in goals-against per game (2.41), at the time the lowest mark in their history. Barkov took a team-leading 1,100 face-offs and had a winning percentage of 57.3 percent, ninth in the NHL among players to play at least 50 games and take at least 500 face-offs. He was also fifth among NHL forwards in plus-minus with a plus-33 rating, which was the second-highest in his 11 NHL seasons.

During the 2024-25 season, Barkov was named Finland's captain for the 4 Nations Face-Off. Ahead of the Stanley Cup Final, he won his third Selke Trophy and joined Patrice Bergeron, Pavel Datsyuk and Rod Brind’Amour as back-to-back winners in the past quarter-century. He helped the Panthers rank among the NHL top 10 in goals-against per game (7th, 2.72), penalty-killing percentage (10th, 80.7 percent) and shots-against per game (5th, 26.2). He ranked fourth among NHL forwards in the puck possession metric SAT percentage (59.3 percent), with Florida accounting for 59.3 percent of all shot attempts 5-on-5 when Barkov was on the ice.

Barkov also received the 2024-25 King Clancy Memorial Trophy given "to the player who best exemplifies leadership qualities on and off the ice and has made a noteworthy humanitarian contribution in his community." He was in a team meeting when he received each award in a special surprise presentation from several girls and boys from Joe DiMaggio Children's Hospital.