The Battle of Alcântara took place on 25 August 1580, near the brook of Alcântara, in the vicinity of Lisbon, Portugal, and was a victory of the Habsburg King Philip II over the other pretender to the Portuguese throne, Dom António, Prior of Crato.

King Philip II of Spain was one of seven who laid claim to the Portuguese throne, and in June 1580 a Spanish army of about 40,000 men[6] (about half of which were German and Italian mercenaries)[7][8] invaded Portugal, under the command of Don Fernando Álvarez de Toledo, Duke of Alba.

[15][16] The Duke of Alba met little resistance and in July landed his forces at Cascais, west of Lisbon.

West of the small brook Alcântara, the Spanish encountered a Portuguese force on the eastern side of it, commanded by António, Prior of Crato (a grandson of King Manuel I of Portugal who had proclaimed himself King as António I) and his lieutenant Francisco de Portugal, 3rd Count of Vimioso.

The battle ended in a decisive victory for the Spanish army, both on land and sea.