Odjick was born in an Algonquin Native Reserve named Kitigan Zibi just outside the town of Maniwaki, Quebec. His father, Joe, was born in 1939 at Rapid Lake to Basil, a trapper and fishing guide, who was later killed in France in 1945 during the Second World War, and Marie-Antoinette Marchand, who was part-French. At the age of nine Joe was sent to a residential school in Spanish, Ontario. The registration number he was given at the school, 29, was later used by Odjick during his playing career. Odjick was the fourth child and only son of six children for Joe and Giselle, after Debbie, Shelley, Judy and ahead of Janique and Dina; there were also several foster children raised by the Odjicks, at least 32. Originally named Wayne, Odjick was soon given a new name, Gino, as the family found out there was another Wayne on the reserve.