Sir Robert Cavendish Spencer KCH (24 October 1791 – 4 November 1830) was an English officer of the Royal Navy.

Well connected by birth, he made a naval career, which attracted the sons of the nobility and also of those from naval backgrounds, to serve under him and, despite liberal politics, worked as a reforming administrator with the future William IV of the United Kingdom.

He was later appointed to HMS Carron, stationed on the coast of North America; was engaged in operations against New Orleans; and was promoted to post rank by the commander-in-chief, Sir Alexander Forrester Inglis Cochrane, on 4 June 1814.

[2] From August 1827 to September 1828 Spencer was private secretary and Groom of the Bedchamber to the Duke of Clarence, then Lord High Admiral.

[2] Spencer died, off Alexandria, on 4 November 1830; he had just been recalled to the United Kingdom as surveyor-general of the ordnance.