Six ships that were built for the Royal Navy have borne the name HMS Ocean. But the name Ocean entered the list from which names are selected for British ships because, in 1759, the Royal Navy captured the French ship named Océan. The British studied the French technology of this ship and admired it. But the ship had to be in bad shape before it would be replaced by a new-build.

The name seems blankly prosaic because the British generally usually use the word "sea", while the French the word "mer". The French ship wasn't named for any of these, but for the Roman mythological giant river, or giant snake Oceanus, which encompassed the flat earth in their mythology. Thus the ships are instead named poetically, but this fact was lost in translation.

• The first Ocean, 90 was a ship of the line built in 1761.

• The second Ocean, 98 was a ship of the line launched in 1805, active in the Napoleonic Wars, and later upgraded to a 110-gun first-rate.

• The third Ocean was originally ordered to be built as a wooden screw ship intended to carry 91 guns. However, the order was changed and she was eventually launched in 1863 as an ironclad of 24 guns. In the late 1860s she served as flagship to the Commander in Chief of the China Station and after an active life of only six years, was paid off in 1872.

• The fourth Ocean was a battleship launched in 1898 and sunk by a mine in 1915.

• The fifth Ocean was an aircraft carrier completed in 1945 and scrapped in 1962.

• The sixth Ocean (L12) is a "Landing Platform, Helicopter" launched in 1995 and on active service as of 2003.