The Treaty of London, signed on 18 August O.S. 1604, concluded the nineteen-year Anglo-Spanish War. The treaty restored the status quo between the two nations. The negotiations probably took place at Somerset House in Westminster and are sometimes known as the Somerset House Conference.

The Anglo-Spanish War (1585–1604) was an intermittent conflict between the Habsburg Kingdom of Spain and the Kingdom of England that was never formally declared. It began with England's military expedition in 1585 to what was then the Spanish Netherlands under the command of the Earl of Leicester, in support of the Dutch rebellion against Spanish Habsburg rule.