HMS Saint Patrick was a 50-gun fourth-rate ship of the line of the English Royal Navy. In 1665, during the Second Anglo-Dutch War, the Navy Committee of Parliament adopted a supplement to their 1664 Programme which provided for one third rate (Warspite) and three fourth rates. The King's chronic financial worries led to the cancellation of the contracts for two of the fourth rates, but the remaining vessel, awarded to Bristol shipbuilder Francis Bayley, was completed in barely a year at the contract price of £6 per ton, measuring slightly larger than her contract dimensions of 100 ft keel length and 32 ft 6 in breadth. Launched in May 1666 at Bristol, the ship proved an outstanding success as a fast, weatherly sailing warship.