The Canadian National Railway (CN; AAR reporting marks CN, CNA, CNIS) is a Canadian Class I railway operated by the Canadian National Railway Company headquartered in Montreal, Quebec.

CN is the largest railway in Canada, in terms of both revenue and the physical size of its rail network and is currently Canada's only transcontinental railway company, spanning Canada from the Atlantic coast in Nova Scotia to the Pacific coast in British Columbia. It also has extensive trackage in the central United States along the Mississippi River valley from the Great Lakes to the Gulf of Mexico.

The railway was referred to as the Canadian National Railways (CNR) between 1918 and 1960 and as Canadian National/Canadien National (CN) from 1960 to present.