The Gunboat War was a naval conflict between Denmark–Norway and Great Britain supported by Sweden during the Napoleonic Wars. The war's name is derived from the Danish tactic of employing small gunboats against the materially superior Royal Navy. In Scandinavia it is seen as the later stage of the English Wars, whose commencement is accounted as the First Battle of Copenhagen in 1801.

A gunboat is a naval watercraft designed for the express purpose of carrying one or more guns to bombard coastal targets, as opposed to those military craft designed for naval warfare, or for ferrying troops or supplies.