The British Mark V tank^{[note 1]} was an upgraded version of the Mark IV tank.

The tank was improved in several aspects over the Mark IV, chiefly the new steering system, transmission and 150 bhp engine, but it fell short in other areas, particularly its insufficient ventilation leading to carbon monoxide poisoning for the crew.^[5] Various versions were fitted with a variety of armament including 6-pounder guns and machine guns.

It was first deployed in July 1918 on the Western Front at the Battle of Hamel; then at the Battle of Amiens, and on the Hindenburg Line during the closing months of World War I.

During the Allied intervention in the Russian Civil War on the White Russian side, four Mark Vs were delivered to Archangelsk, four to Reval, Estonia,^[6] and around 70 were delivered to Novorossisk in southern Russia. The survivors were captured and used by the Red Army.^[7]

There were two main further variants, the lengthened Mark V* and a few Mark V**s with a more powerful engine and wider tracks. A planned Mark V*** was never built. There are eleven surviving Mark V tanks. The Mark VIII tank was an enlarged Mark V with greater power: only those with the Liberty engine saw post-war service in the US. A further unarmed development was the Mark IX tank, one of the first armoured personnel carriers, which saw limited use in Britain after the war.

In general the Mark V was successful, especially given its limited service history, and somewhat primitive design dating back to 1915.