The Battle of Basra lasted from 21 March to 6 April 2003 and was one of the first battles of the 2003 invasion of Iraq. The British 7 Armoured Brigade fought their way into Iraq's second-largest city, Basra, on 6 April coming under constant attack by the Iraqi Army 51st Division and Fedayeen Saddam, while elements of the British Parachute Regiment cleared the 'old quarter' of the city that was inaccessible to vehicles. Entering Basra had only been achieved after two weeks of conflict, which included the biggest tank battle of the war by British forces when the Royal Scots Dragoon Guards destroyed 14 abandoned Iraqi tanks on the 27 March.

The Battle of Nasiriyah was fought between the US 2nd Marine Expeditionary Brigade and Iraqi forces from 23 March to 2 April 2003 during the US-led invasion of Iraq. On the night of 24–25 March, the bulk of the Marines of Regimental Combat Team 1 passed through the city over the bridges and attacked north towards Baghdad. Other elements remained in the city to fight its defenders, who put up stiff resistance and inflicted several dozen casualties on coalition forces, more than in most other battles during the invasion. Resistance ceased on 1 April.

The Battle of Umm Qasr was the first military confrontation in the Iraq War. At the start of the war, one of the first objectives was the port of Umm Qasr. On 21 March 2003, as allied forces advanced across Southern Iraq, an amphibious landing force captured the new port area of Umm Qasr. The assault was spearheaded by Royal Marines of the British 3 Commando Brigade, augmented by U.S. Marines of the American 15th MEU and Polish JW GROM troops. Iraqi forces in the old town of Umm Qasr put up unexpectedly strong resistance, requiring several days' fighting before the area was cleared of defenders. The port was finally declared safe and reopened on 25 March 2003.

The Battle of Al Faw began on 20 March 2003 and continued for four days, as part of the 2003 invasion of Iraq.

The Battle of Najaf was a major battle in the 2003 U.S. invasion of Iraq. The first stage of the battle was fought when the U.S. 3rd Infantry Division fought to surround the town. The second stage was fought when soldiers from the U.S. 101st Airborne Division fought to clear and secure the city.

Operation Viking Hammer was an unconventional warfare operation during the Iraq War which took place in northern Iraq, commonly known as Iraqi Kurdistan. The goal of the operation was to eliminate Ansar al-Islam and dismantle the Islamic Emirate of Kurdistan. Ansar al-Islam was established by former Al-Qaeda members in 2001 as a Kurdish Salafist movement that imposed a strict application of Sharia in villages it controlled.

The Battle of Samawah took place during the 2003 invasion of Iraq as American troops fought to clear the city of Iraqi forces. The city had been bypassed during the advance on Baghdad, leaving the task of clearing it to American paratroopers of the 82nd Airborne Division with mechanized infantry and armor provided by units of the 1st Battalion, 41st Infantry Regiment, and 2-70th Armor Battalions, along with 3rd platoon 59th Chemical Company tasked with finding and removing any potential chemical or biological weapons. The battle was the largest sustained urban combat that paratroopers of the 82nd Airborne had been involved in since World War II.

Operation Northern Delay occurred on 26 March 2003 as part of the 2003 U.S. invasion of Iraq. It involved dropping paratroopers into Northern Iraq. It was the last large-scale combat parachute operation conducted by the U.S. military since Operation Just Cause.