Berkeley was born in Ixelles, Brussels, the third son (but only legitimate son) of George Lennox Rawdon Berkeley (1827–1888) by his wife, Cécile (died 1914), daughter of Edward Drummond, count of Melfort and divorced wife of Admiral Sir Fleetwood B. R. Pellew.
On the death of his father in 1888 he assumed the title of Earl of Berkeley, and he established his right to the peerage in 1891.
Berkeley lived with his parents abroad, and was educated in France before returning to England to prepare for entrance into the Royal Navy, being crammed at Dr. Burney's Academy for the purpose.
He entered HMS Britannia in 1878, and served on various ships from 1880 to 1887, including a period of service on the China Station.
He then studied for a period at the Royal College of Science, during which he became interested in crystals.