The 1914–15 NHA season was the sixth season of the National Hockey Association and played from December 26, 1914, until March 3, 1915. Each team played 20 games. The Ottawa Senators won the NHA championship in a two-game, total goal playoff against the Montreal Wanderers. The Senators, however fell to the Vancouver Millionaires of the Pacific Coast Hockey Association in the Stanley Cup championship. It was the second 'World's Series' between the NHA and the PCHA for the Stanley Cup.
Along with Montreal Nationals president A. L. Caron, player Art Ross attempted to organize a new hockey league with teams in Ottawa, Montreal, Toronto and Boston. The arena owners in all of the cities turned down the new league and killed the idea. Ross was suspended by the NHA, but by January 7, Mr. Ross was reinstated. He signed with Ottawa.