The affair of Fielding and Bylandt was a brief naval engagement off the Isle of Wight on 31 December 1779 between a Royal Navy squadron, commanded by Commodore Charles Fielding, and a naval squadron of the Dutch Republic, commanded by rear-admiral Lodewijk van Bylandt, escorting a Dutch convoy. The Dutch and British were not yet at war, but the British wished to inspect the Dutch merchantmen for what they considered contraband destined for France, then engaged in the American War of Independence.
Bylandt attempted to avoid the engagement by offering to allow the British to inspect the ships' manifests, but when Fielding insisted on a physical inspection, Bylandt put up a brief show of force, before striking his colours. The British squadron then seized the Dutch merchantmen and took them as prizes to Portsmouth, followed by the Dutch squadron. The incident worsened the already strained diplomatic relations between Great Britain and the Dutch Republic. It also contributed to the formation of the First League of Armed Neutrality to which the Dutch acceded in December of 1780.