The Canadian Joint Incident Response Unit (CJIRU) (French: Unité interarmées d'intervention du Canada, UIIC) of the Canadian Armed Forces was created "to provide timely and agile broad-based CBRN (chemical, biological, radiological and nuclear) support to the Government of Canada in order to prevent, control and mitigate CBRN threats to Canada, Canadians, and Canadian interests".

[1][4] It is a sub-unit of the Canadian Special Operations Forces Command (CANSOFCOM).

Subsequent to the terrorist attacks of September 11, 2001, and the Chief Review Services Report on Nuclear, Biological and Chemical Defence of the same year, it became evident that the Canadian Forces needed to increase the breadth of its nuclear, biological and chemical defence (NBCD) capabilities.

The federal government, under then–Prime Minister Jean Chrétien, allotted $30 million in the December 2001 budget to enhance this capability and create the Joint Nuclear, Biological and Chemical Defence Company (JNBCD Coy).

Due to the requirement for rapid deployment of the unit, CJIRU is based alongside airlift assets at 8 Wing Trenton, Ontario.