The Right Honourable Clarence Decatur Howe (January 15, 1886 - December 31, 1960) was a leading Canadian politician. In the 1940s and 1950s he was known as the "Minister of Everything".

Howe was born in Waltham, Massachusetts, United States and attended Massachusetts Institute of Technology where he received an engineering degree. He emigrated to Canada in 1903 to teach at Dalhousie University. Howe was successful as a professor, but found it dreary and left to design grain elevators on the Canadian prairies. In 1916 he formed his own firm at Port Arthur, Ontario, that specialized in elevator design. His business prospered and he was soon very wealthy. The Great Depression hit his business hard, however, and it folded in 1935.

Howe decided to move to politics, and was elected as one of Mackenzie King's Liberals in that same year for Port Arthur, Ontario. In 1936 he entered the cabinet, becoming Minister of Transport. Howe maintained close relations with Canadian business leaders and guaranteed their support of the Liberals, despite their conservative tendencies. During the Second World War Howe played a pivotal role becoming Minister of Munitions and Supply. His role in the war effort was recognised by his appointment, in 1946, to the Imperial Privy Council enabling him to use the honorific of Right Honourable.

After the war Howe came to symbolize the Liberal government of Louis St. Laurent first as Minister of Reconstruction and then as Minister of Trade and Commerce. Howe ran much of the government and was the second most powerful man in the country. He became well_known for arrogance, however. He described question period in the House of Commons as "children's hour" and was frequently quoted as saying "What's a million?" a phrase he never used. This culminated in the debate on the Trans-Canada Pipeline where Howe tried to force the public-private partnership through parliament.

In part because of the pipeline and Howe's behaviour, two decades of Liberal rule came to an end in a surprise defeat to John Diefenbaker's Progressive Conservatives in 1957. Many observers were shocked when Howe himself lost his northern Ontario seat.

Despite these failures, Howe is still today viewed as one of the men who made Canada into a modern industrial power. Howe played an important role in setting up many of the pillars of the Canadian economy such as Air Canada, the St. Lawrence Seaway, and CN Rail. The C.D. Howe Building, the home of Industry Canada in Ottawa, and the C.D. Howe Institute, an economic policy think tank, are named after him.

On his passing in 1960, C. D. Howe was interred in the Mount Royal Cemetery in Montreal, Quebec.