The 2004–05 OPJHL season is the 12th season of the Ontario Provincial Junior A Hockey League (OPJHL). The thirty-five teams of the North, South, East, and West divisions competed in a 49-game schedule. Come February, the top eight teams of each division competed for the Frank L. Buckland Trophy, the OJHL championship. The winner of the Buckland Cup, the St. Michael's Buzzers, competed in the Central Canadian Junior "A" championship, the Dudley Hewitt Cup, and finished 2nd. The DHC was hosted and won by the Georgetown Raiders who moved to the 2005 Royal Bank Cup but lost in the semi-final.