The 1917–18 PCHA season was the seventh season of the professional men's ice hockey Pacific Coast Hockey Association league. Season play ran from December 28, 1917, until March 8, 1918. The season was reduced to 18 games per team. The Seattle Metropolitans club would be regular-season PCHA champions, but lost the play-off to the Vancouver Millionaires. The Millionaires then played in the Stanley Cup Finals series against Toronto, the NHL champions. Toronto won the best-of-five series 3-2 to win the Cup.

The Pacific Coast Hockey Association (PCHA) was a professional ice hockey league in western Canada and the western United States, which operated from 1911 to 1924 when it then merged with the Western Canada Hockey League (WCHL). The PCHA was considered to be a major league of ice hockey and was important in the development of the sport of professional ice hockey through its innovations.