The Battle of Badr (Arabic: غَزْوَةُ بَدِرْ Arabic pronunciation: [ɣaz'wat'u ba'dir]), also referred to as The Day of the Criterion (Arabic: يَوْمُ الْفُرْقَانْ, Arabic pronunciation: [jawm'ul fur'qaːn]) in the Qur'an and by Muslims, was fought on 13 March 624 CE (17 Ramadan, 2 AH), [2] near the present-day city of Badr, Al Madinah Province in Saudi Arabia. Muhammad, commanding an army of his Sahaba, defeated an army of the Quraysh led by Amr ibn Hishām, better known as Abu Jahl. The battle marked the beginning of the six-year war between Muhammad and his tribe. Prior to the battle, the Muslims and the Meccans had fought several smaller skirmishes in late 623 and early 624.

Muhammad took keen interest in capturing Meccan caravans after his migration to Medina, seeing it as repayment for his people, the Muhajirun. A few days before the battle, when he learnt of a Makkan caravan returning from the Levant led by Abu Sufyan ibn Harb, Muhammad gathered a small expeditionary force to capture it. Abu Sufyan, learning of the Muslim plan to ambush his caravan, changed course and took a longer route away from Muhammad's base at Medina and sent a messenger to Mecca, asking for help. Abu Jahl commanded an army nearly one-thousand strong, approaching Badr and encamping at the sand dune al-'Udwatul Quswa.

Badr was the first large-scale engagement between the Muslims and Quraysh Meccans. Advancing from the north, the Muslims faced the Meccans. The battle began with duels between the warriors on both sides, following which the Meccans charged upon the Muslims under a cover of arrows. The Muslims countered their charge and broke the Meccan lines, killing several important Quraishi leaders including Abu Jahl and Umayyah ibn Khalaf.

The Muslim victory strengthened Muhammad's position; The Medinese eagerly joined his future expeditions and tribes outside Medina openly allied with Muhammad.[3] The battle has been passed down in Islamic history as a decisive victory attributable to divine intervention, and by other sources to the strategic prowess of Muhammad.