The 1999–2000 NHL season was the 83rd regular season of the National Hockey League. With the addition of the expansion Atlanta Thrashers, 28 teams each played 82 games. This was the first season played in which teams were awarded a point for an overtime loss. The New Jersey Devils defeated the defending champion Dallas Stars for their second Stanley Cup championship. During the regular season, no player reached the 100-point plateau, the first time this had happened in a non-lockout season since the 1967–68 season. Also, in the 2000 Stanley Cup playoffs, the New Jersey Devils overcame a three games to one deficit against the Philadelphia Flyers to win the Eastern Conference Finals.

Throughout the regular season and playoffs, teams wore a patch celebrating the turn of the millennium (see above).

Beginning this season, teams would earn one point for an overtime loss in the regular season instead of zero. It was hoped that this change would stop teams from playing very defensively during the overtime to guarantee the single point from a tie. The number of ties had been going up for some years and the NHL was hoping to counter this trend and did so quite successfully with this rule change.^[1]

This season was also the start of the NHL's partnership with ABC, who would televise a few regional games every season, as well as games three through seven of the Stanley Cup Finals. ESPN, who with the ABC deal renewed their contract with the NHL, continued to show regular season and playoff games as well as the first two games of the Stanley Cup Finals.

Wayne Gretzky's jersey number, 99, was retired league-wide on February 6, 2000.

The 1999–2000 season was the inaugural year for the Atlanta Thrashers. They would join the Southeast Division, marking the return of the NHL to Atlanta since the Atlanta Flames moved to Calgary in 1980. It was also the first year for the Carolina Hurricanes' home rink, the Raleigh Entertainment and Sports Arena, the Los Angeles Kings played their first season at the Staples Center after 32 seasons at the Great Western Forum, and the Colorado Avalanche played their first season at the Pepsi Center.

A new award, the Roger Crozier Saving Grace Award, was introduced this season for the goaltender with the best save percentage.

The standings will record three points for games decided in overtime: 2 to the winning team, and 1 to the loser. In addition, overtimes will be played with four skaters per side, instead of five.^[2]

League wide: an NHL 2000 patch was worn this season for the New Millennium.

Anaheim: Jade Alternates Retired. Eggplant pants with Jade Stripes are restored.

Atlanta: White jerseys have the team logo, while the road darks have the alternate mark. The team wore Ignargural season patches for their first season.

Carolina: Shade of red is darkened. In addition to the NHL 2000 Patch, the Hurricanes wore two other patches this season, one celebrated the opening of the Raleigh Entertainment and Sports Arena, and the other was in Memory of Steve Chiasson, who died in a single-vehicle, alcohol-involved crash after the Hurricanes were eliminated in the 1999 Stanley Cup Playoffs.

Chicago: The tan outline on the crest is removed.

Colorado: Shade of Burgundy is darkened from 1998-1999

Dallas: The alternates from 1998-1999 become the basis of the team's new home Uniform. the actual 1998-1999 Alternates become the new road uniform.

Los Angeles: New Purple alternates introduced.

New York Rangers: Navy Blue Lady Liberty Alternates return.

Ottawa: The Alternates from the 1998-1999 become the new Road Uniforms

Phoenix: Crest on the alternates get a sand-colored outline.

Tampa Bay: the alternate jerseys are dropped.

Toronto: All-star game patch worn for 2000 NHL All Star Game. the Alternates worn during the 1998-1999 season for the last year at Maple Leaf Gardens go on a one year hiatus.

Divisions: AT – Atlantic, NE – Northeast, SE – Southeast

Z – Clinched Conference; Y – Clinched Division; X – Clinched Playoff spot

Divisions: CEN – Central, PAC – Pacific, NW – Northwest

bold – Qualified for playoffs; p – Won Presidents' Trophy; y – Won division

Two upsets occurred in the first round as seventh-place Pittsburgh defeated the second-place Washington Capitals in five games and eighth-place San Jose defeated the first-place St. Louis Blues in seven games. Both Pittsburgh and San Jose lost in the second round to end their seasons. In the East, fourth-place New Jersey Devils defeated fifth-place Florida Panthers, third-place Toronto Maple Leafs and first-place Philadelphia Flyers to advance to the final. In the West, the second-place Dallas Stars defeated the seventh-place Edmonton Oilers, eighth-place San Jose Sharks, and the third-place Colorado Avalanche to advance to the final.

The New Jersey Devils defeated the Dallas Stars four games to two to win the Stanley Cup. Scott Stevens of New Jersey was awarded the Conn Smythe Trophy as the playoffs' most valuable player.

Note: GP = Games played; G = Goals; A = Assists; Pts = Points

Note: GP = Games played; Min – Minutes Played; GA = Goals Against; GAA = Goals Against Average; W = Wins; L = Losses; T = Ties; SO = Shutouts

Source: 2001 NHL Yearbook

The following is a list of players of note who played their first NHL game in 1999–2000 (listed with their first team, an asterisk(*) marks debut in playoffs):

The following is a list of players of note that played their last game in the NHL in 1999–2000 (listed with their last team):

Trading deadline: March 14, 2000.^[5]