HMS Acheron
A class
General Characteristics
Displacement:	1,350 tons (Codrington 1,540 tons, RCN ships 1,337 tons)
Length:	323 ft (98.5 m) (Codrington 343, RCN ships 320 ft (97.5 m))
Beam:	32 ft (9.8 m)
Draught:	12.2 ft (3.7 m)
Propulsion:	2 steam turbines, 3 boilers, 2 shafts, 34,000 shp (25 MW)
Speed:	35 knots (65 km/h)
Range:	5400 nautical miles (10,000 km) at 15 knots (28 km/h)
Complement:	138 (185 Codrington)
Armament:	Original configuration: 4 x 4.7 in (119 mm) guns (5 x 4.7 in (119 mm) guns in Codrington) 8 x 0.5 in (12.7 mm) machine guns 8 x 21 in (533 mm) torpedo tubes

The A class was a class of eleven destroyers of the Royal Navy, which included the flotilla-leader Codrington . All ships were commissioned in the early 1930s. Two ships, Saguenay and Skeena were built for the Royal Canadian Navy.

The class introduced limited changes in weaponry and protection, introducing quad torpedo mounts, having eight of them, though it was reduced to four in most of the class. The flotilla leader, Codrington, was larger than the rest of the class, at 343 ft (105 m) compared to 320 ft (98 m). Their displacement was 1,540 tons and an increased crew complement of 185, though the specialised role of a flotilla-leader was numbered in the Royal Navy.

The class saw much service in World War II, being involved in convoy protection and anti-submarine warfare in home waters and the North Atlantic. The survivors saw a number of modifications, as did nearly all, if not all, warship classes in the war. The reduction of their four x single 4.7 in (119 mm) guns to two to three, and the replacement of the 0.5 in (12.7 mm) machine gun with the far more capable 20 mm Oerlikon gun, of which six were added. A 76 mm gun was also added to the class during the war.

The two Canadian ships were slightly modified from the British ships, with their bow strengthened with heavier plating to enable them to perform in areas with ice. Their length was three feet smaller than their British counterparts, and their displacement also decreased, though only slightly. Saguenay was heavily damaged in a collision with the merchant ship Azara and was consigned to the role of training ship after being repaired.

Seven of the eleven ships of the class were sunk in World War II. Acasta and Ardent were sunk on 8 June 1940 by Scharnhorst and Gneseisnau west of Narvik during the Norwegian Campaign. Codrington was sunk by German air attack at Dover on 27 July 1940. Acheron was sunk by a mine off the Isle of Wight on 17 December 1940. Achates was sunk by two large German heavy cruisers Admiral Hipper and Lützow. Arrow was so heavily damaged when the ammunition ship Fort la Monte blew up on 17 October 1944 at Taranto that she could not be repaired. Skeena was wrecked in a storm off Iceland on 25 October 1944.

The four surviving ships were scrapped by the end of the 1940s.