Winter Classic Souvenir "Dueling" Puck (Chicago Blackhawks vs. Detroit Red Wings), 2009 Wrigley Field.

The NHL Winter Classic is an annual event held by the National Hockey League (NHL) on or around New Year's Day in which a regular-season hockey game is played outdoors, in an area hosted by an NHL team. The first outdoor NHL game was the Heritage outdoor game held in Edmonton in 2003 between Edmonton and Montreal. It became an annual event in 2008. It featured American teams for its first years, but the 2013 NHL Winter Classic will feature its first Canadian team, as the Toronto Maple Leafs play against the Detroit Red Wings. The first Winter Classic was held in 2008.

The first Winter Classic was held January 1, 2008, between the Buffalo Sabres and Pittsburgh Penguins at Ralph Wilson Stadium in Orchard Park, New York.  The game had an NHL-record crowd of 71,217 fans in attendance. The success of the 2008 NHL Winter Classic led the NHL to schedule a second one for 2009, held at Wrigley Field in Chicago, Illinois, on January 1, 2009, matching the Detroit Red Wings against the Chicago Blackhawks. That game had the highest American television ratings of any hockey game in 33 years. The success of the 2009 NHL Winter Classic has solidified "the Classic" as an annual event from then on.