Sir Edmund St. John Debonnaire John Monson, 3rd Baronet, K.C.M.G. (9 September 1883—1969) was a British diplomat.
Monson was the second son of Sir Edmund Monson, 1st Baronet and succeeded his elder brother to the baronetcy created in 1905 for his father (also a diplomat). He was educated at Eton College
He entered the British diplomatic service in 1906 and served in junior capacities in Constantinople, Tokyo, Paris, and Tehran. He was promoted to Embassy Counsellor in 1923.[1] In 1926, he was appointed British Minister in Colombia.[2] This was followed by the same post in Mexico from 1929 to 1934,[3] and to the Baltic States from 1934 to 1937.[4] He was Minster in Sweden from 1938 to 1939.[5] He was appointed K.C.M.G. in 1938, two years after succeeding his brother to the baronetcy.