HMS Diamond was a Topaze-class protected cruiser of the Royal Navy.

In the years 1911 and 1912, she served with the 3rd Flotilla, operating as a senior officers ship.

[1] When World War I broke out in 1914, Diamond was assigned to the 5th Battle Squadron, where she would serve as an escort ship for the battleship HMS Lord Nelson.

[2] In 1915 she was reassigned to the 3rd Battle Squadron of the Grand Fleet, and in 1918 she was reassigned to the Mediterranean Fleet, serving the role of a Coastal Motor Boat carrier.

[2] Diamond remained as part of the Mediterranean Fleet until 1921, when she was recalled back to England, where she was decommissioned and sold for scrap on 9 May 1921.