James Blair Seaborn, CM (18 March 1924 – 11 November 2019) was a Canadian diplomat and civil servant best remembered for the Seaborn Mission of 1964–1965 in connection with the Vietnam War and for heading the "Seaborn Panel" of the 1990s that examined the subject of how to dispose of nuclear waste in Canada. Seaborn would ultimately become the best-known of all of Canada's ICC representatives, but the Canadian historian Victor Levant noted that "he did not gain this notoriety until long after his tour of duty." The Seaborn Mission is a controversial subject with opinions sharply divided to its purpose and morality.