The National Hockey League (NHL) began its second century in 2017. Since then, the NHL has grown from 30 to 32 teams with the addition of the Vegas Golden Knights and the Seattle Kraken to the Western Conference. The COVID-19 pandemic was a major disruption to the league during the 2019–20, 2020–21 and 2021–22 seasons. The NHL played games without spectators in controlled conditions. The Arizona Coyotes indefinitely suspended operations following the 2023–24 season; the team's hockey assets, including its roster and coaches, were transferred to the newly-founded Utah Hockey Club (now Utah Mammoth) franchise. This era saw the emergence of Connor McDavid as a superstar, becoming the first player in nearly 30 years to record 150 points in a single season, among other accomplishments.

Background Prior to 2017, the NHL's last expansion was in 2000, adding the Columbus Blue Jackets and Minnesota Wild to bring the number of teams to thirty. After the Atlanta Thrashers relocated to Winnipeg in 2011, sixteen of the teams in the league were in the Eastern time zone; the conferences remained balanced with fifteen teams each until the league realigned in 2013. Following the realignment, all sixteen teams in the Eastern time zone were placed into the Eastern Conference and the remaining fourteen teams were placed in the Western Conference, leaving the conferences unbalanced. Beginning in 2013, the NHL started hearing from groups interested in acquiring an NHL franchise. Interest was shown from groups in Seattle, Kansas City, Las Vegas and Quebec City. Groups in the west were favoured by the NHL so as to even out the team distribution. Seattle did not have an arena, while Las Vegas and Quebec City were building new rinks. In June 2015, the NHL announced that it was officially considering expansion and set an application deadline for July 20, 2015 for teams to begin play in 2017. Prospective teams had to pay to apply, of which $2 million was refundable. Las Vegas and Quebec City progressed to stage two of the process in August 2015. Ultimately, only Las Vegas was approved by the league's Board of Governors on June 22, 2016, to pay an expansion fee of . Las Vegas was not considered to be a hotbed for ice hockey. To ensure the new team's success on the ice and attendance, the NHL made more players available in the expansion draft from the existing teams. This led to a large number of trade deals by Las Vegas, as existing teams sought to protect players strategically. The shorter lists of protected players meant high-profile players such as Marc-Andre Fleury, James Neal, Eric Staal and Sami Vatanen were available for selection in the expansion draft.

The second century

Vegas and Seattle additions

In 2017, the Vegas Golden Knights joined the NHL, increasing league membership to 31 teams. In their first season as a franchise, the Golden Knights became an immediate success, capturing the Pacific Division title en route to an appearance in the 2018 Stanley Cup Final, a feat never seen before in North American professional sports. They lost the series 4–1 to the Washington Capitals, losing four straight games after a 6–4 victory in the first game. Vegas returned to the Finals in , defeating the Florida Panthers four games to one to win their first Stanley Cup, and becoming the second-fastest expansion team to win their first Cup. Vegas reached the Final for a third time in nine seasons in 2026, but fell to the Carolina Hurricanes in six games.

On December 4, 2018, it was announced that a team in Seattle, later named the Seattle Kraken, would be the 32nd team in the league. Upon debuting in 2021, the Kraken joined the Pacific Division, with the Arizona Coyotes moving to the Central Division. After a dismal inaugural season that saw them finish near the bottom of the league, the Kraken reached the playoffs for the first time in their second season, defeating the defending champion Colorado Avalanche in the first round before falling to the Dallas Stars in seven games in the second round.

Multiple first-time champions, Boston's historic season, and Floridian success The six–year streak of a Pittsburgh Penguins, Chicago Blackhawks, or Los Angeles Kings Stanley Cup win came to an end in . The Washington Capitals, not seen in the Stanley Cup Final since their loss to the Detroit Red Wings in , won their first Stanley Cup in franchise history, defeating the aforementioned Golden Knights in five games. In , the St. Louis Blues, who had not made the Finals since , won their first Stanley Cup championship, defeating the Boston Bruins in seven games. As previously mentioned, the expansion Golden Knights also won their first Stanley Cup in 2023, becoming the second-fastest expansion team to win the Cup.

The season saw the Tampa Bay Lightning record one of the most successful regular seasons in NHL history. In their Presidents' Trophy-winning campaign, the team's 62 wins tied the Detroit Red Wings' then-NHL all-time record, with Nikita Kucherov's 128 points then the most in a single season during the salary cap era. The team suffered a humiliating first-round playoff exit, being swept by the wild card Columbus Blue Jackets in one of the largest upsets in NHL history, and becoming the first Presidents' Trophy winners to be swept in the first round. The Lightning subsequently rebounded, defeating the Dallas Stars to win the Stanley Cup the following year after a pandemic-shortened season and modified playoff format. The Lightning then repeated as champions in the similarly shortened and modified season, defeating the Montreal Canadiens in the Stanley Cup Final. Tampa Bay additionally reached a third consecutive Stanley Cup Final in , but lost to the Colorado Avalanche in six games.

In 2022, the year after the Lightning's second consecutive Stanley Cup victory, the cross-state Florida Panthers won the Presidents' Trophy for the first time, despite head coach Joel Quenneville resigning early in the season as a result of the 2010 Chicago Blackhawks sexual assault scandal. The Panthers would go on to win their first playoff series in 26 years, defeating the Washington Capitals in the first round in six games, before being swept by the Lightning in the second round. The following offseason, the Panthers hired Paul Maurice as head coach and traded for Calgary Flames forward Matthew Tkachuk. After narrowly making the playoffs as a wild card, the Panthers upset the heavily favored, record-breaking Boston Bruins in the first round in seven games, despite facing a 3–1 deficit. Florida would reach the 2023 Stanley Cup Final, their first since 1996, but fell to the Vegas Golden Knights in five games. After defeating the Lightning in the first round of the 2024 Stanley Cup playoffs, the Panthers returned to the Finals the following year, marking the fifth consecutive Finals featuring a Florida-based team. Despite nearly blowing a 3–0 series lead, the Panthers defeated the Edmonton Oilers in seven games to win their first Stanley Cup. The following season, the Lightning and Panthers once again matched up in the first round of the 2025 playoffs, with the Panthers winning in five games despite being the lower seed. Florida went on to match Tampa Bay's achievement in reaching a third straight Final, and the sixth consecutive for the state of Florida, facing Edmonton again in a rematch of the previous season. After splitting the first four games, the Panthers won the series in six games to capture their second consecutive Stanley Cup, and the fourth in six years for their home state. The seven–year streak of Florida-based teams reaching the Final came to an end in , which saw the Carolina Hurricanes defeat the Golden Knights in six games to win their second Stanley Cup championship. Despite this, Carolina's victory marked the sixth Stanley Cup championship in seven years won by a Sun Belt-based team.

In the same season as the Panthers' wild-card run to the Finals, the 2022–23 Boston Bruins recorded statistically the greatest regular season campaign in NHL history. Winning the Presidents' Trophy for the fourth time, Boston's 65 wins and 135 points both set new NHL records, surpassing the 62 wins shared by the aforementioned 1995–96 Detroit Red Wings and 2018–19 Tampa Bay Lightning and 132 points held by the 1976–77 Montreal Canadiens. The team set multiple other records as well, becoming the fastest team to 100 points and 50 wins in NHL history, as well as setting a new record of 14 consecutive home wins to start the season. The Bruins suffered a first-round elimination to the Panthers—similarly to the 2018–19 Lightning—after holding a 3–1 series lead four games into the series.

Further outdoor games During the NHL's 100th anniversary celebrations in 2017, two one-off outdoor games were held in Eastern Canada. The NHL Centennial Classic took place at Toronto's BMO Field on January 1, 2017, and it featured a rematch of the 2014 Winter Classic between the Red Wings and Maple Leafs. On December 16, 2017, the NHL 100 Classic between the Canadiens and Senators was played at TD Place Stadium in Ottawa, Canada, to commemorate the first games of the NHL in 1917.

A series of NHL outdoor games took place on February 20 and 21, 2021, at the Edgewood Tahoe Resort near Lake Tahoe in Nevada. The NHL Outdoors at Lake Tahoe event saw the Golden Knights play the Avalanche in the first game, and the Bruins and Philadelphia Flyers in the second. Unlike previous NHL outdoor games, it was not held in a stadium or ballpark but in a golf course overlooking the lake; no fans were in attendance due to the COVID-19 pandemic. This event replaced both the 2021 Winter Classic and Stadium Series due to the shortened season (see below).

The Stadium Series continued to move into southern and non-traditional markets. On March 3, 2018, the Capitals hosted the Toronto Maple Leafs at the Navy–Marine Corps Memorial Stadium in Annapolis, Maryland, in a partnership between the NHL and the United States Armed Forces. The 2022 edition was contested between the Tampa Bay Lightning and Nashville Predators at Nissan Stadium in Nashville; this was followed by the 2023 edition, which featured the Capitals and the Carolina Hurricanes at Carter–Finley Stadium on the campus of North Carolina State University in Raleigh. The 2024 event returned north to MetLife Stadium just outside New York City and held multiple games for the first time since 2016; in two of the highest-attended games in hockey history, the Flyers took on the New Jersey Devils in the first game, while the New York Rangers took on the New York Islanders in the second. Following the 2026 edition held in Tampa, the Stadium Series will remain in the south in 2027, with the Stars scheduled to host the 2027 Stadium Series at AT&T Stadium in Arlington, Texas.

The Winter Classic additionally saw a move southward, with the 2020 NHL Winter Classic taking place at the Cotton Bowl between the Predators and Stars. The 2024 event, meanwhile, featured a battle of expansion teams, with the Golden Knights and Kraken facing off in Seattle's T-Mobile Park. Continuing the southward trend even further, both the 2026 Winter Classic and 2026 Stadium Series were held in Florida, with the Panthers hosting the former at loanDepot Park in Miami, and the Lightning hosting the latter at Raymond James Stadium in Tampa. In a return to a colder-weather market, the 2027 Winter Classic is scheduled to be hosted by the Utah Mammoth at Rice-Eccles Stadium in Salt Lake City.

The Heritage Classic continued to be held irregularly; most notably, the 2022 edition became the first to be officially hosted by an American team, with the Buffalo Sabres playing as the home team against the Maple Leafs at Tim Hortons Field in Hamilton, Ontario.

Olympic participation