Nelson Trusler Johnson (April 3, 1887 – December 3, 1954) was the United States ambassador to the Republic of China from 1935–41, and to Australia from 1941–45.
Johnson was born in the family row house located at 1st and East Capitol Street (now a part of the location of the United States Supreme Court) in Washington, D.C. He spent a part of his early life in Newkirk, Oklahoma and then Kildare, Oklahoma. He then returned to Washington to complete his schooling at Sidwell Friends School near 8th & I Street NW. He then went to George Washington University and pledged to the Delta Tau Delta fraternity. In his freshman year he decided to take the Foreign Service Examination, claiming his residency as Oklahoma. Successful, he received an appointment to the Foreign Service of the United States as appointments were made based on one's home state. He spent his entire adult life in the service of his government. Johnson specialized in China and the Far East, first as a student interpreter, then as consular officer, Chief of the Division of Far Eastern Affairs, next as Assistant Secretary of State, and then as Minister and Ambassador on assignments to China leading up to World War II. He served as ambassador to Australia during World War II (1941-1945).
Johnson first became intimately involved in shaping American policy toward China in 1925 when he assumed the office of Chief of the Division of Far Eastern Affairs in the State Department. From 1928 to May 1941 he was first assigned as Minister Plenipotentiary, then as Ambassador Extraordinary and Minister Plenipotentiary, to China. During those years he contributed heavily to determining the conduct of US relations with that country, based primarily on Johnson's personal papers in the Library of Congress and the published and unpublished State Department records that address his activities over the 1925–1941 period emphasizing his ideas and suggestions regarding American policy to that country.