The Acasta class was a class of twenty destroyers built for the Royal Navy under the Naval Programme of 1911 - 1912 that saw service during World War I. They were the last class of Royal Navy destroyers to have mixed names with no systematic theme When the class was designated as "K", names beginning with that letter were allocated to the ships but never used. The class saw extensive wartime service and seven were lost, including four at the Battle of Jutland.

The Acheron class was a class of twenty-three destroyers of the British Royal Navy, all built under the 1910–11 Programme and completed between 1911 and 1912, which served during the First World War. A further six ships were built to the same design for the Royal Australian Navy as River-class destroyers. There was considerable variation between the design and construction of ships within this class, which should be considered as more of a post-build grouping than a homogeneous class.