The Thunder Bay Junior A Hockey League (TBJHL) was a Canadian Junior ice hockey league that existed from c. 1920 to 1980. The TBJHL operated in Northwestern Ontario, primarily in the Thunder Bay region.
The Thunder Bay Junior A Hockey League was what is now known as a Major Junior hockey league from roughly 1920 until the Canadian Amateur Hockey Association realignment of 1970. After 1970, the TBJHL was relegated to Tier II Junior A and competed for the Manitoba Centennial Trophy until the league folded in 1980.
Thunder Bay and the TBJHL was considered on the border region of what people would call Eastern Canada and Western Canada. Due to its location, the Thunder Bay league often switched from East to West year-to-year in National playdowns. The league's remoteness resulted in keeping the league's few teams from competing in the neighbouring Manitoba Junior Hockey League or Northern Ontario Junior Hockey League, making the league's existence a necessity to the region's hockey community.
Thunder Bay Junior A Hockey League teams made the Memorial Cup finals four times in fifty years, winning Canada's top junior hockey prize in 1922 (Fort William War Veterans) and 1948 (Port Arthur West End Bruins).
The TBJHL is the indirect predecessor of the Superior International Junior Hockey League who brought a Junior A league back to the region in 2001, 21 years after the TBJHL folded.
Although hockey in Thunder Bay dates back well before 1920, the Thunder Bay Junior Hockey League first competed in Memorial Cup action in 1921. In only their second year of operation at the Junior A level, the league celebrated their first National championship as the Fort William War Veterans defeated the Regina Pats 5-4 and tied them 3-3 to win the championship. To get there, the Vets had to defeat Toronto Aura Lee in the Eastern Canada final, beating them 5-3 in a one-game showdown.