HMS Ursa was a modified Admiralty R-class destroyer that served in the Royal Navy during the First World War.

Ursa was one of eleven Modified R-class destroyers ordered by the British Admiralty in March 1916 as part of the Eighth War Construction Programme.

A total of 296 long tons (301 t) of fuel oil were carried, giving a design range of 3,450 nautical miles (6,390 km; 3,970 mi) at 15 knots (28 km/h; 17 mph).

[3] Armament consisted of three single 4-inch (102 mm) Mk V QF guns on the ship's centreline, with one on the forecastle, one aft on a raised platform and one between the funnels.

[3] Laid down by Palmers Shipbuilding and Iron Company in Jarrow, Ursa was launched on 23 July 1917 and completed on 16 October.

[6] On 17 November 1917, Ursa took part in the Second Battle of Heligoland Bight in support of the 1st Cruiser Squadron, led by Vice-Admiral Trevylyan Napier in Courageous.