James Harley Marsh, CM (born September 10, 1943) is a Canadian editor, writer and encyclopedist.
Marsh found his métier in a summer job with educational publisher Holt, Rinehart and Winston, learning all aspects of the business from copy editing to the inner workings of the typesetting and printing industries.
In 10 years he edited 60 volumes in the series while co-authoring his first textbook on Canadian history, New Beginnings.
After 33 years as the founding editor of The Canadian Encyclopedia, James Marsh retired on March 31, 2013.
There Marsh drew up plans for Canada's first comprehensive encyclopedia since the 1950s and hired some 40 staff, 400 consultants and several thousand contributors.