The eight ships of the J class were ordered on 25 March 1937, and Jaguar was laid down at the Dumbarton shipyard of Denny on 25 November 1937. She was launched on 22 November 1938 and commissioned on 12 September 1939. Jaguar was long between perpendiculars and overall, with a beam of and a draught of. Displacement was standard and deep load. Two Admiralty three-drum boilers fed steam at and to Parsons to two sets of Parsons single-reduction geared-steam turbines, rated at. This gave a design speed of at trials displacement and at full load. As completed, Jaguar had a main gun armament of six QF Mark XII guns in three twin mountings, two forward and one aft. These guns could only elevate to an angle of 40 degrees, and so were of limited use in the anti-aircraft role, while the aft mount was arranged so that it could fire forwards over the ship's superstructure to maximise the forward firing firepower, but was therefore incapable of firing directly aft. A short range anti-aircraft armament of a four-barrelled 2-pounder "pom-pom" anti-aircraft mount and eight.50 in machine guns in two quadruple mounts was fitted, while torpedo armament consisted of ten torpedo tubes in two quintuple mounts.
Service
On commissioning, Jaguar joined the 7th Destroyer Flotilla based at Grimsby, operating off Britain's east coast. On 11 October, the ship ran aground in the Firth of Forth and was under repair until November. She was refitted at the Caledon Shipbuilding & Engineering Company's Dundee yard from 15 March 1940 to 1 May that year, with leaks being rectified and her fuel tanks modified. On 20 May 1940, Jaguar, along with sister ships and and the corvette, escorted Naval trawlers as they cut the undersea telegraph cables between the UK and Borkum. On 26 May 1940, the Royal Navy set Operation Dynamo in motion, to rescue trapped British troops from Dunkirk and the surrounding area. On 27 May, Jaguar, together with Javelin and, was deployed to screen the evacuation operations from the North. On 28 May, Jaguar and other destroyers rescued survivors from the sinking of. Jaguar landed 370 troops picked up from the beaches of Bray-Dunes at Dover early on 29 May.Later that day she was ordered to embark troops from Dunkirk harbour. Jaguar, Grenade and were attacked by German dive bombers as they arrived at Dunkirk at about noon, with Gallant damaged by a near miss and forced to turn back. Jaguar and Grenade berthed side-by-side on the East Pier at Dunkirk. She embarked about 1000 troops before leaving the harbour at about 15:50 hr, when she was attacked by dive bombers and near missed by four bombs, which severed a steam pipe, which disabled her engines and knocking out her steering. She was towed clear of a wreck by the destroyer, which along with the coaster Rika, took off Jaguars troops. Later that day, Jaguar managed to restore power and returned to Dover under her own steam. Jaguar was sent to the Humber for repair, returning to service on 23 June. In October 1940 she was transferred to Portsmouth, and on 11 October, took part in Operation Medium, when the destroyers of the 5th Destroyer Flotilla, including Jaguar, escorted the battleship during a bombardment of Cherbourg harbour. From 14 October to 1 November, Jaguar was refitted at Devonport, being fitted with degaussing coils. In later February 1941 she took part in Operation Abstention, where she engaged the Italian destroyer Crispi off Kastelorizo, disengaging after Crispi scored a hit on her searchlight; that March she took part in the Battle of Cape Matapan. Jaguar was struck by two torpedoes fired by the and sank off Sidi Barrani, Egypt, on 26 March 1942 with the loss of 3 officers and 190 of her crew. 8 officers and 45 crewmen were rescued by the naval whaler HMS Klo.
