HMS Urchin was a Modified Admiralty R-class destroyer which served with the Royal Navy during the First World War. The Modified R class added attributes of the Yarrow Later M class to improve the capability of the ships to operate in bad weather. The destroyer was the third ship in the Navy to be named after the sea urchin and the first in the class to be built by Palmers in Jarrow. Launched in 1917, Urchin served with the Grand Fleet, seeing action in the Second Battle of Heligoland Bight. After the war, the destroyer was remained in service until being retired and sold to be broken up in 1930.

The first R class were a class of 62 destroyers built between 1916 and 1917 for the Royal Navy. They were an improvement, specifically in the area of fuel economy, of the earlier Admiralty M-class destroyers. The most important difference was that the Admiralty R class had two shafts and geared turbines, compared with the three shafts and direct turbines of the Admiralty M class, but in appearance the R class could be distinguished from its predecessors by having the after 4-inch gun mounted in a bandstand. The Admiralty ordered the first two of this class of ships in May 1915. Another seventeen were ordered in July 1915, a further eight in December 1915, and a final twenty-three in March 1916.