Who Killed Canadian History? is a 1998 book by the Canadian historian J. L. Granatstein. The book argues that Canadians lack national unity because of their failure to teach their country's history. Granatstein contends that multiculturalism, social historians and weak history teaching standards are responsible for Canada's lack of a historical narrative. He advocates for a greater emphasis on the study of Canadian history in schools and university history departments, especially political and military history.

The 1980s and 1990s saw increasing disputes among Canadian historians, splitting between political and social historians. The historian Adam Chipnick describes Who Killed Canadian History? as "the pinnacle" of these disputes, termed the "history wars". According to Granatstein, the expanding reach of social historians in the history departments of Canadian universities has resulted in ineffectual and uneducated graduates. He further argues that poor teaching standards and political correctness have led to historical ignorance among Canadians, leaving them unable to properly appreciate their present and future. He suggests a number of measures to increase historical awareness, including implementing national teaching standards.

Upon release, the book was a national bestseller in Canada. It received positive reviews from the press, but was negatively received by most historians, leading to major debates in Canadian history journals. While many historians agreed with Granatstein's contention that Canadians are ignorant of their past, they disputed the book's argument that the blame lay with social historians and multiculturalism. Several criticized the book as poorly written and unfocused in its argumentation. Following its publication, the provinces Alberta and Manitoba implemented new history curricula emphasizing Canadian content; Historica Canada was founded, an organization whose stated goal is increasing awareness of Canadian history; and Granatstein was appointed director and CEO of the Canadian War Museum. Granatstein released an extensively revised and updated version of the book in 2007, though it received little attention compared to the original version.

J. L. Granatstein is a Canadian historian and former professor. While serving in the Canadian Army, he received a BA from the Royal Military College of Canada and an MA from the University of Toronto. After receiving a PhD in 1966 from Duke University, he taught history at York University until his retirement in 1995. Stephen Azzi of Carleton University describes Granatstein as the "most prolific Canadian historian of his generation", and Peter Farrugia of Wilfrid Laurier University calls him "one of Canada's best known historians". In the 1970s and 80s, Granatstein's writing focused primarily on the Canadian government during the Second World War – especially Prime Minister William Lyon Mackenzie King – before pivoting to military history in the 1990s.

Historian Leon Fink writes that, besides his history writing, Granatstein is best known for "his stinging neoconservative critique" of Canadian post-secondary institutions – especially tenure, journal subsidies, multiculturalism and political correctness. Granatstein wrote polemics against Canadian universities with his fellow historians David Bercuson and Robert Bothwell, published as The Great Brain Robbery: The Decline of Canada's Universities (1984) and Petrified Campus: The Crisis in Canada's Universities (1997). In his 1990 book on the breakdown of the Meech Lake Accord, journalist Andrew Cohen argues that Granatstein, alongside other contemporary historians Michael Bliss and Ramsay Cook, was among those who instigated public opposition to the eventually failed constitutional deal, writing that the historians "brought their sense of the country's past to the accord and declared it a tearing of the national fabric."

Disputes between Canadian historians, dubbed the "history wars", marked the 1980s and 1990s. Historian Cecilia Morgan writes that historians were increasingly "[working] within the structures (some might say strictures) of the academy and their departments", causing "considerable anxiety" for others in the field. Historian Christopher Dummitt classifies the two groups as the older generation, made up of "nationalists" who focus on studying historical leaders, and the younger generation of "inclusivists", approaching the field differently to study the stories of those generally passed over in previous research. Historian Adam Chipnick describes Granatstein as occupying the former group, and sees the book Who Killed Canadian History? as marking "the pinnacle (or the nadir) of ... the 'history wars'."

Really, who cares about the history of [a] housemaid's knee in Belleville in the 1890s?

Historian Graham Carr describes the book as fitting into a larger tradition of historiography books written since the 1960s, each of which lament a decline in the popular appreciation of history. Historian Robert Wright and journalist Andrew Cohen argue that the book advances points made by Michael Bliss in a 1991 Creighton Centennial Lecture, which Bliss later published in a Journal of Canadian Studies piece titled "Privatizing the Mind: The Sundering of Canadian History, the Sundering of Canada." Bliss's piece argues that, beginning in the 1970s, Canadian history-writing shifted from professional historians to "Via Rail nationalists" who "identified Canada and things Canadian with ... the age of big government, universal social welfare programs, and subsidized culture." Granatstein had previously contributed to the dispute by criticizing what he saw as the increasingly narrow focus of social historians, referring to their study as "the history of [a] housemaid's knee in Belleville in the 1890s". Journalist Ray Conlogue writes the statement "hit a nerve", and historian Ken Osborne writes the dismissal "sent the historical establishment, not to mention ministries of education from coast to coast, to the battlements in self-defence." Having been consistently condemned for the assertion, Granatstein later reflected, "[i]t was an overstatement ... but it reflected my increasing uneasiness and complete frustration at the way our history is taught."