The Stadium Series is one of the series of regular season outdoor games played in the National Hockey League (NHL). This event is distinct from the NHL's other two series of outdoor games, the NHL Winter Classic and NHL Heritage Classic outdoor games, played on New Year's Day. Games in the Stadium Series have been held in either late January, February or early March in a football or baseball stadium in the United States. The first Stadium Series was held in 2014 and consisted of seven teams participating in four games held in three venues. Since 2017, only one game has been scheduled per year.