The St James' Day Battle, also known as the Battle of the North Foreland and the Battle of Orfordness, August 4 to August 5, 1666 was a naval battle of the Second Anglo-Dutch War, fought between the fleets of England and the United Provinces commanded by Admiral Michiel de Ruyter. (August 4 was July 25—St James' day in the Julian calendar then in use in England). In The Netherlands the battle is known as the Two Days Battle.

The battle was a clear English victory, but the Dutch only lost two ships and the twin disasters of the Great Plague and the Great Fire of London left Charles II without the funds to continue the war. The Dutch quickly recovered to inflict a severe blow on the English navy in the Raid on the Medway in 1667.