List of battlecruisers of World War I

This is a list of battlecruisers of World War I. A battlecruiser, or battle cruiser, was a capital ship built in the first half of the 20th century. They were similar in size, cost, and carried similar armament to battleships, but they generally carried less armour to obtain faster speeds. The first battlecruisers were designed in the United Kingdom, in the first decade of the century, as a development of the armoured cruiser, at the same time as the dreadnought succeeded the pre-dreadnought battleship. The original aim of the battlecruiser was to hunt down slower, older armoured cruisers and destroy them with heavy gunfire. However, as more and more battlecruisers were built, they increasingly became used alongside the better-protected battleships.

Battlecruisers served in the navies of Britain, Germany, the Ottoman Empire, Australia and Japan during World War I, most notably at the Battle of the Falkland Islands and in the several raids and skirmishes in the North Sea which culminated in a pitched fleet battle, the Battle of Jutland. British battlecruisers, in particular, suffered heavy losses at Jutland, which modern research has revealed was due to dangerous ammunition handling practises rather than the weak armour usually attributed as the weakness. By the end of the war, capital ship design had developed with battleships becoming faster and battlecruisers becoming more heavily armoured, blurring the distinction between a battlecruiser and a fast battleship. The Washington Naval Treaty, which limited capital ship construction from 1922 onwards, treated battleships and battlecruisers identically, and the new generation of battlecruisers planned was scrapped under the terms of the treaty.

The list includes armed vessels that served during the war and in the immediate aftermath, inclusive of localized ongoing combat operations, garrison surrenders, post-surrender occupation, colony re-occupation, troop and prisoner repatriation. Some uncompleted battlecruisers are included, out of historic interest.