San Fernando (Spanish pronunciation: [ˈsaɱ feɾˈnando], "Saint Ferdinand") is a town in the province of Cádiz, Spain.

The people from San Fernando are locally known as "Cañaíllas" or "Isleños".

In history, the city played a paramount role when in 1810 during the Peninsular War led by Napoleon, San Fernando and Cádiz were the only parts of Spain which were never occupied by the French, until the French withdrawal in defeat from Spain in 1814.

The deputies elected to the Cortes of Cádiz met in the Teatro Cómico, and started preparation of the first liberal constitution of Spain, which was approved in the neighbouring city of Cádiz in 1812.

Flamenco singer Camarón de la Isla was born in San Fernando.