The Battle of Sagrajas (23 October 1086), also called Zalaca or Zallaqa, is a battle between the Almoravid army led by general Yusuf ibn Tashfin and a Christian army led by the Castilian King Alfonso VI.

The battleground is later called az-Zallaqah (in English "slippery ground") because the warriors were slipping all over the ground due to the tremendous amount of blood shed that day, and this gives rise to its name in Arabic.