The Justice Annex was a building just east of the Supreme Court of Canada and west of Parliament Hill in Ottawa, Canada. Built in 1942–3, it was the last surviving representative of many similar temporary buildings erected during the Second World War to house the rapidly growing number of government employees. This building was built to house Royal Canadian Mounted Police (RCMP) officers. It later became the headquarters of C.D. Howe's Department of Munitions and Supply.