The A-class torpedo boats were a class of German single-funnelled torpedo boat/light destroyer designed by the Reichsmarineamt for operations off the coast of occupied Flanders in the First World War. The "A" designation was to avoid confusion with older classes and designs. They were classed officially as "coastal torpedo boats" (German: Küstentorpedoboote) to differentiate from larger, ocean-going torpedo boats.

Six groups of vessels were built under the class between 1914 and 1918, increasing in displacement from 109 tons to 335 tons. All had a raised forecastle, shallow draught, and carried one (for most) or two (for A1-A25) 17.7 in (45 cm) torpedo tubes amidships.

All 25 were ordered in 1914, and were designed and built by A.G. 'Vulcan', at their Hamburg yard.

• A2 and A6 were sunk by British destroyers on 1 May 1915 during the Battle off Noordhinder Bank.
• A3 was sunk on 7 November 1915 en route from Kiel to Danzig.
• A15 was sunk by French destroyers on 23 August 1915.
• A13 was bombed in dock at Ostend on 16 August 1917.
• A10 was sunk by mines off Flanders on 7 February 1918.
• A7 and A19 were sunk by British and French destroyers off the Flanders coast on 21 March 1918.
• A1, A18 and A21–A25 surrendered and were stricken between 1921 and 1922.
• A11 and A17 were sunk during the Kapp Putsch in 1920.
• A4, A12 and A14 were abandoned in Antwerp after the German evacuation at the end of the First World War. Taken over by Belgium. Remained operational until 1927.^[3]
• A5, A8, A9, A16 and A20 were interned in the Netherlands at the end of the war, and handed over to Belgium as reparations in 1919. Decommissioned in 1927 and most scrapped. A20 remained in use as training vessel and captured by Germans in 1940.^[3] Scrapped 1948.^[2]

All 30 were ordered in two batches - 24 vessels in 1915, and 6 added later. All were designed and built by F. Schichau Werke, at their Elbing yard. The second batch were 2 tonnes heavier, and had a breadth of 5.82 metres (18ft 5.25in).

• A26–A29, A31, A33–A39, A41, A44–A46, A48, A49, and A52–A55 were surrendered and stricken between 1920 and 1921.
• A30, A40, A42 and A47 interned in the Netherlands at end of the war and allocated to Belgium in 1919 under Versailles Treaty. Discarded in 1927.^[3]
• A32 was sunk during the "Operation Albion" on 25 October 1917, raised and repaired in 1923, and served as Sulev in the Estonian Navy. Taken by Russia in October 1940, it was renamed Аметист ("Amethyst") and served in the Soviet Navy as a patrol vessel, then reduced to a tender in 1942 until scrapped in 1950.^[5][6]
• A43 was scrapped in 1943.
• A50 was mined in the North Sea on 17 November 1917.
• A51 was scuttled at Fiume on 29 October 1918.

These 42 vessels were ordered in three batches - A56 to A67 in 1916, A80 to A91 in 1917, and A96 – A113 in 1918. Designed by A. G. Vulcan, who built all of them except for A83, A84 and A85, which were built by Howaldtswerke at Kiel, while the hulls of A64 to A67 were subcontracted to Seebeckwerft. None of the 1918 batch of 18 vessels were ever completed, and they were all stricken on 3 November 1918, some being up to 35% complete (these were broken up on the stocks) but none being launched.

• A56–A58 were mined in 1918.
• A59, A60 and A61 caused severe damage to HMS Terror on 19 October 1917.^[8]
• A59 was transferred to Poland in 1921, becoming ORP Ślązak. Became target ship in 1937 and captured by Germans in 1939. Sunk under tow.^[9]
• A60 was mined in 1917.
• A61 and A62 were transferred to Britain in 1920, scrapped in 1923.
• A63 and A66 were given to France in 1920, scrapped in 1923.
• A64 was transferred to Poland 1921 becoming ORP Krakowiak. Stricken in October 1936 and scrapped.^[9]
• A65 was given to Brazil, and scuttled in Britain.
• A67 was scrapped incomplete in 1921.
• A80 was transferred to Poland in 1921 as ORP Góral. Renamed Podhalanin in 1922. Converted to oil hulk in 1939. Sunk by German bombers while under tow on 24 September 1939.^[10]
• A81, A86–A91 were stricken in 1920.
• A82 was scuttled at Fiume in 1918.
• A83, A84 and A85 were scrapped incomplete, 1919.

These twelve vessels were ordered in 1916, and were designed and built by F. Schichau at Elbing.

• A68 was transferred to Poland in 1921, becoming ORP Kujawiak. Converted to oil hulk 1939. Sunk by German bombers 3 September 1939 off Danzig.^[10]
• A68, A69, A70, A74, A75, A76, and A78 all surrendered in September 1920 (and so were stricken) and were scrapped in 1922/23.
• A71, A72, A73, A77 and A79 were all sunk by mines in the North Sea during 1918.

These last four vessels were designed and built by F. Schichau Werke, at their Elbing yard, with a slight variation in their dimensions from the 1916 design. The first two served in a minesweeper flotilla and the last two in an escort flotilla prior to the surrender.

• All four vessels were scrapped at Bo'ness in 1923 (A93 in 1922).