The Battle of Badr or sometimes called The Raid of Badr (Arabic: غَزْوَةُ بَدْرٍ [ɣazwatu badr]; Ghazwahu Badr), also referred to as The Day of the Criterion (Arabic: يَوْمُ الْفُرْقَانْ, Arabic pronunciation: [jawm'ul fur'qaːn]; Yawm al-Furqan) in the Qur'an and by Muslims, was fought on 13 March 624 CE (17 Ramadan, 2 AH), 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 among Muslims as Abu Jahl. The battle marked the beginning of the six-year war between Muhammad and his tribe. The Battle of Badr took place after five or six unsuccessful attempts by the Muslims to intercept and raid Meccan trade caravans between 623 and early 624 CE.

Muhammad took keen interest in capturing Meccan caravans and their wealth after his migration to Medina. 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 raid 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. Amr ibn Hisham 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. 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.

After the Hijra (migration to Medina) in 622 CE, the population of Medina chose Muhammad to be the leader of the community. Muhammad's followers decided to raid the caravans of the Meccans as they passed by Medina.

In early 624, a caravan of the Quraysh led by Abu Sufyan ibn Harb carrying wealth and goods from the Levant (possibly Gaza) was returning to Mecca. It was carrying merchandise worth 50,000 dinars and guarded by 70 men. The caravan was extraordinarily large, possibly because several smaller caravans may have grouped together for safety. All the leading Meccan financiers had a share in this trading venture, and thus had a strong interest in it returning.

Muhammad learned of the caravan and decided to intercept it for two reasons. First, was the continuation of the policy to recover wealth from the Quraysh, as the Quraysh had confiscated Muslims' properties in Mecca after the hijrah. Secondly, a successful attack would impress the Meccans and could act as a deterrent against a future attack on Medina.

Abu Sufyan sent word to Mecca that the caravan was in danger, asking for reinforcements to cover the caravan as it passed by Medina. Traditional Muslim sources write that Abu Sufyan's spies had informed him of Muslim preparations to attack, a view accepted by Ramadan. But Watt writes given that it took the Meccan army a week to get to Badr, Abu Sufyan must have sent his request before the Muslim preparations began. Watt points out Abu Sufyan was "one of the most astute men in Mecca" and must have anticipated the Muslim attack.