Richard Mitchelson Campbell CMG (28 August 1897 – 17 November 1974) was a New Zealand economist, civil servant (holding the position of Chairman of the Public Service Commissioner), and diplomat.

He attended Whangarei High School and in 1914 joined the public service working at the Department of Education.

In February 1918 he enlisted in the army, only to be discharged a month later as mobilisation was being scaled back.

After accompanying finance minister Walter Nash to Britain and Europe, from 1940 to 1945 he had an unhappy period as Secretary of the New Zealand High Commission in London, as Campbell and the High Commissioner, ex-politician Bill Jordan disliked each other.

[1] He served as Acting High Commissioner to the United Kingdom in 1958 following five years as the official secretary.