Fall of Baghdad-April 2003: Three weeks into the invasion, US-led Coalition forces moved into Baghdad. Units of the Iraqi Special Republican Guard led the defence of the city. The rest of the defenders were a mixture of Republican Guard units, Regular army units, Iraqi Fedayeen, and non-Iraqi Arab volunteers. Initial plans were for Coalition units to surround the city and gradually move in, forcing Iraqi armor and ground units to cluster into a central pocket in the city, and then attack with air and artillery forces.

This plan soon became unnecessary, as an initial engagement of armored units south of the city saw most of the Republican Guard's assets destroyed and routes in the southern outskirts of the city occupied. On April 5 Task Force 1-64 Armor of the U.S. Army's Third Infantry Division executed a raid, later called the "Thunder Run", to test remaining Iraqi defenses, with 29 tanks and 14 Bradley Armored Fighting Vehicles advancing to the Baghdad airport.

They met heavy resistance, but were successful in reaching the airport. US troops faced heavy fighting in the airport, and were even temporarily pushed out, but eventually secured the airport. The next day, another brigade of the 3rd I.D. attacked into downtown Baghdad and occupied one of the palaces of Saddam Hussein in fierce fighting. US Marines also faced heavy shelling from Iraqi artillery as they attempted to cross a river bridge. The Iraqi commander directed the fire, and one shell from an Iraqi gun killed or wounded four Marines, but the river crossing was successful. The Iraqis managed to inflict heavy casualties on the American forces near the airport from defensive positions but suffered severe casualties from air bombardment.

Within hours of the palace seizure and with television coverage of this spreading through Iraq, U.S. forces ordered Iraqi forces within Baghdad to surrender, or the city would face a full-scale assault. Iraqi government officials had either disappeared or had conceded defeat, and on April 9, 2003, Baghdad was formally occupied by Coalition forces. Much of Baghdad remained unsecured however, and fighting continued within the city and its outskirts well into the period of occupation. Saddam had vanished, and his whereabouts were unknown.

On April 10, a rumor emerged that Saddam Hussein and his top aides were in a mosque complex in the Al Az'Amiyah District of Baghdad. Three Companies of Marines were sent to capture him. The Marines came under heavy fire from rocket-propelled grenades, mortars, and assault rifles. One Marine was killed and 20 were wounded, but neither Saddam or any of his top aides were found.

U.S. forces supported by mortars, artillery, and aircraft continued to attack Iraqi forces still loyal to Saddam Hussein and non-Iraqi Arab volunteers. U.S. aircraft flying in support were met with Iraqi anti-aircraft fire. On April 12, the final resistance to U.S. forces was mounted. One Marine was killed, but by late afternoon, all fighting had ceased. A total of 34 U.S. soldiers and 2,320 Iraqi soldiers and Fedayeen were killed.

Many Iraqis celebrated the downfall of Saddam by vandalizing the many portraits and statues of him together with other pieces of his cult of personality. One widely publicized event was the dramatic toppling of a large statue of Saddam in Baghdad's Fardus Square. This attracted considerable media coverage at the time. As the British Daily Mirror reported,

"For an oppressed people this final act in the fading daylight, the wrenching down of this ghastly symbol of the regime, is their Berlin Wall moment. Big Moustache has had his day."

As Staff Sergeant Brian Plesich reported in On Point: The United States Army in Operation Iraqi Freedom,

"The Marine Corps colonel in the area saw the Saddam statue as a target of opportunity and decided that the statue must come down. Since we were right there, we chimed in with some loudspeaker support to let the Iraqis know what it was we were attempting to do..." "Somehow along the way, somebody had gotten the idea to put a bunch of Iraqi kids onto the wrecker that was to pull the statue down. While the wrecker was pulling the statue down, there were Iraqi children crawling all over it. Finally they brought the statue down"

The fall of Baghdad saw the outbreak of regional, sectarian violence throughout the country, as Iraqi tribes and cities began to fight each other over old grudges. The Iraqi cities of Al-Kut and Nasiriyah launched attacks on each other immediately following the fall of Baghdad to establish dominance in the new country, and the US-led Coalition quickly found themselves embroiled in a potential civil war. US-led Coalition forces ordered the cities to cease hostilities immediately, explaining that Baghdad would remain the capital of the new Iraqi government. Nasiriyah responded favorably and quickly backed down; however, Al-Kut placed snipers on the main roadways into town, with orders that invading forces were not to enter the city. After several minor skirmishes, the snipers were removed, but tensions and violence between regional, city, tribal, and familial groups continued.

US General Tommy Franks assumed control of Iraq as the supreme commander of the coalition occupation forces. Shortly after the sudden collapse of the defense of Baghdad, rumors were circulating in Iraq and elsewhere that there had been a deal struck (a "safqua") wherein the US-led Coalition had bribed key members of the Iraqi military elite and/or the Ba'ath party itself to stand down. In May 2003, General Franks retired, and confirmed in an interview with Defense Week that the US-led Coalition had paid Iraqi military leaders to defect. The extent of the defections and their effect on the war are unclear.

US-led Coalition troops promptly began searching for the key members of Saddam Hussein's government. These individuals were identified by a variety of means, most famously through sets of most-wanted Iraqi playing cards.

On July 22, 2003 during a raid by the U.S. 101st Airborne Division and men from Task Force 20, Saddam Hussein's sons Uday and Qusay, and one of his grandsons were killed in a massive fire-fight.

Saddam Hussein was captured on December 13, 2003 by the U.S. Army's 4th Infantry Division and members of Task Force 121 during Operation Red Dawn.