Richmond joined the Royal Navy as a cadet in 1885, serving on the Australian Station and in the Hydrographic Service before qualifying as a torpedo officer in 1897.

After the disappointing 31 May – 1 June 1916 Battle of Jutland resulted in the appointment of his admirer Admiral David Beatty as Grand Fleet CIC in December[6] 1916, assisted by his memorandums that predicted the beginning of unrestricted submarine warfare by Germany beginning 1 February 1917, he received command of HMS Conqueror in the Grand Fleet in April 1917, after which he served as director of staff duties and training in 1918, then commanded HMS Erin in 1919.

[6] In early 1917 Richmond lobbied hard for convoy protection of merchant shipping in the North Sea, but the Admiralty resisted despite mounting losses, waiting until the end of April to experiment.

Following his forced retirement from the Royal Navy in 1931,[6][7] the University of Cambridge appointed him Vere Harmsworth Professor of Imperial and Naval History, an academic chair he held from 1934 to 1936.

In March 1942 Richmond published an article in The Fortnightly Review which charged that the British defeat in the Battle of Singapore in February 1942 was due to "the folly of not providing adequately for the command of the sea in a two-ocean war".

[8] In his last book Statesmen and Sea Power (1946), he charged that the defeat was sealed by "the illusion that a Two-Hemisphere Empire can be defended by a One-Hemisphere Navy".