The first siege of Gibraltar was a battle of the Spanish Reconquista that took place in 1309. The battle pitted the forces of the Crown of Castile (mostly those from the military councils of the city of Seville) under the command of Juan Núñez II de Lara and Alonso Pérez de Guzmán, against the forces of the Emirate of Granada who were under the command of Sultan Muhammed III and his brother, Abu'l-Juyush Nasr.

The battle resulted in a victory for the Crown of Castile, one of the few victories in what turned out to be a disastrous campaign. The taking of Gibraltar greatly increased the relative power of Castile on the Iberian Peninsula though the actual city was later recaptured by Muslim forces during the third siege of Gibraltar in 1333.