The First Battle of al-Faw was a battle of the Iran–Iraq War, fought on the al-Faw peninsula between 10 February and 10 March 1986. The Iranian operation is considered to be one of Iran's greatest achievements in the Iran–Iraq War. The Iranians were able to capture the al-Faw peninsula, cutting off Iraqi access to the Persian Gulf in the process; this in turn hardened Iraqi attitudes to prosecute the war. The Faw peninsula was later recaptured by Iraqi forces near the end of the war.

On 9 February 1986, Iran launched Operation Dawn 8, a sophisticated and carefully planned amphibious assault across the Shatt al-Arab (Arvand Rud) river against the Iraqi troops defending the strategic al-Faw peninsula, which connects Iraq to the Persian Gulf. The Iranians defeated the Iraqi defenders, mostly Iraqi Popular Army, capturing the tip of the peninsula, including Iraq's main air control and warning center covering Persian Gulf, as well as limiting Iraq's access to the ocean. Iran managed to maintain their foothold in Al-Faw against several Iraqi counter-offensives, including Republican Guard assaults and chemical attacks, for another month despite heavy casualties until a stalemate was reached.

The First Battle of al-Faw was a major success for Iran who now held an important strategic position, but worried other states in the region, primarily in Kuwait and Saudi Arabia, who increased their support for Iraq. The battle damaged the prestige of Saddam Hussein and the Iraqi government, who began extensively improving defenses for the threatened major city of Basra. Although the battle officially ended in March 1986, intermittent clashes continued for two years until April 1988, when Iraq recaptured the al-Faw peninsula at the Second Battle of al-Faw.

The Iran–Iraq War had been fought for nearly 6 years. While the Iranians had driven the Iraqis off of their soil in 1982, Iranian efforts to invade Iraq and cause the downfall of the regime of Saddam Hussein had been fruitless. Iran had suffered due to a lack of spare parts and in its inability to replace lost equipment, and relied heavily on human wave attacks and light infantry warfare. Meanwhile, the Iraqis (especially after 1982) were heavily supported by foreign nations. The war bogged down into a stalemate.

In the face of increasing Iraqi armament and manpower, as well as increasing problems on their own side, Iran could no longer rely on outnumbering Iraqi troops.[51] While the infantry and human wave assaults would remain key to their attacks throughout the war, Iran began to rely more heavily on infiltration and surprise attacks, as a part of limited light infantry warfare [50]. In contrast to Iraq's static defences and heavy armour, Iran began training troops in infiltration, patrolling, night-fighting, marsh warfare, and mountain warfare.[51] They also began training thousands of Revolutionary Guard commandos in amphibious warfare,[75] as southern Iraq is marshy and filled with wetlands. Iran used speedboats to cross the marshes and rivers in southern Iraq and landed troops on the opposing banks, where they would dig and set up pontoon bridges across the rivers and wetlands to allow heavy troops and supplies to cross. Transport helicopters were used as well, ferrying troops to the battlefield.[51] Iran largely focused on infiltrating through areas that were difficult for Iraqi armour, air power, and artillery to be used, such as valleys, the marshes of southern Iraq, and the mountains of northern Iraq.[39]

Iran began to plan for a major offensive. While deceptively making it seem like the attack was to be against the southern Iraqi city of al-Basra (like most of Iran's attacks had been), the attack was really aimed at the southern al-Faw peninsula, touching the Persian Gulf, and the only area of Iraq that touched the open ocean.

The operation was planned by Iran's army chief of staff and the Iranian defense minister. It was planned entirely by professional military officers, but the battlefield commanders were a mix of regular army and Revolutionary Guards officers. The Iraqis were taken by surprise, as they had not expected the Iranians to be able to land troops on the peninsula. The Iranians hoped to cut off Iraq from the Persian Gulf, making the country landlocked, and threaten Basra from the south. More importantly, Iran hoped to deliver a series of blows against Iraq that would lead to its downfall via attrition warfare. The operation was to be called Operation Valfajr 8 (Dawn 8).

On 9 February 1986, the Iranians launched Operation Dawn 8 (Persian: عملیات والفجر ۸), in which 100,000 troops comprising five Army divisions and 50,000 men from the Revolutionary Guards and the Basij paramilitary advanced in a two-pronged offensive into southern Iraq. Unlike the earlier offensives, Dawn 8 was planned entirely by professional Army officers, all of whom were former officers of the Imperial Iranian Army during the rule of the Shah. The Iranians launched a feint attack against Basra (around al-Qurnah) from 9–14 February, attempting to split Iraq's 3rd and 7th Corps; this was stopped by the Iraqis. Meanwhile, the main Iranian blow fell on the strategically important Al-Faw peninsula, which fell after only 24 hours of fighting. Iran's northern forces launched human wave attacks, while the southern forces launched an armored attack against the enemy. Both attacks were stopped with heavy Iraqi firepower, and the Iranians suffered 4,000 casualties. However, the Iraqis became convinced that this was the main point of attack, and diverted their forces to that sector; this is now recognised as a deception. Instead, Iran's primary objective was Iraq's al-Faw peninsula, the only area in Iraq that touched the Persian Gulf.