The Assault on Cádiz was a part of a protracted naval blockade of the Spanish port of Cádiz by the Royal Navy, which comprised the siege and the shelling of the city as well as an amphibious assault on the port itself from June to July 1797. After the battle of Cape Saint Vincent the British fleet led by Lord Jervis and Sir Horatio Nelson had appeared in the Gulf of Cádiz. In the first days of June the city was bombarded, causing slight damage to the Spanish batteries, navy and city. Nelson's objective was to force the Spanish admiral Jose Mazarredo to leave the harbour with the Spanish fleet. The Spanish response was to build gunboats and small ships to protect the entrance of the harbour from the British. By early July, after a series of failed attacks led by Rear Admiral Nelson, and with the British ships taking huge fire from the Spanish forts and batteries, the British withdrew and the siege was lifted. The naval blockade, however, lasted until 1802.

Cádiz is a city in Spain and the capital of the Province of Cádiz, in the autonomous community of Andalusia. It is located in the southwest of the Iberian Peninsula off the Atlantic Ocean separated from neighbouring San Fernando by a narrow isthmus.