The Young Communist League of Canada was founded in 1923 as the youth wing of the Communist Party of Canada. It was one of numerous Young Communist Leagues around the world, the most notable being the Komsomol in the USSR upon which all other Young Communist Leagues became modelled.
The YCL had its greatest strength and influence during the Great Depression of the 1930s when it was involved in anti-poverty campaigns such as the On to Ottawa Trek. It also played an important role in organizing the Mackenzie-Papineau Battalion in which many YCL members fought on the Republican side during the Spanish Civil War. The YCL was also involved in anti-fascist activities.
The YCL was banned along with the Communist Party in 1941. Canadian Communists organized themselves as the Labour-Progressive Party while the YCL was transformed into the National Federation of Labour Youth. After the war, the NFLY was a founding member of the World Federation of Democratic Youth.
The NFLY, along with the LPP and the left in general faced serious repression during the Cold War. The NFLY attempted to fight growing anti-Communist sentiment through efforts such as its campaign in support of Julius and Ethel Rosenberg as well as campaigning against the Korean War.
The NFLY changed its name to the Socialist Youth League of Canada in the mid-1950s but was unable to revive its faltering fortunes which were tied to the split in the Labour-Progressive Party. This split ensued following the 1956 Soviet invasion of Hungary. By the end of the decade the SYLC was defunct.
In the early 1960s the Communist Party of Canada (as it was again known) restarted its youth wing, again calling it the Young Communist League. The YCL was active in campaigns such as support for the Cuban Revolution and opposition to the Vietnam War but was largely sidelined by more radical youth groups aligned with the New Left and was unable to play a central role in the youth radicalization of the 1960s and 1970s though it did succeed in attracting some new youth into the Communist Party.
The YCL was liquidated around 1991 due to a serious crisis in the CPC that followed the 1991 collapse of the Soviet Union. The Communist Party split with George Hewison and a majority of the party's membership, including a significant majority of the youth, either joining the Cecil-Ross Society or dropped out of communist politics altogether. An attempt was made to refound the YCL in 1994 but was unsuccessful. A subsequent attempt, around 2000, was also unsuccessful when a number of youth refused to follow the CPC's instruction to call the youth wing the Young Communist League. Instead a youth group called the Red Star Youth Collective was formed in Toronto. It soon renamed itself Young Left and split with the Communist Party over doctrinal and organizational issues.
In 2004 a conference was held which formed a Young Communist League Organizing Committee with the intent of relaunching the YCL. Since then the YCL has spread across the country and continues to grow.