Staff at Baghdad's Yarmuk Hospital on Saturday said Aqila al-Hashimi, a Shia Muslim and career diplomat, had been shot twice in the stomach, once in the shoulder and once in the leg.
She was later removed to a US army medical facility.
Hospital officials said three of her bodyguards had also been wounded, one critically.
Elsewhere, five US soldiers were reportedly wounded in a spate of attacks in north and central Iraq. Aljazeera's correspondent has reported US forces arrested about 60 residents from one village in the restive northern region.
Al-Hashimi was reportedly shot when her car was ambushed close to her home in western Baghdad.
A policeman at Yarmuk hospital said Hashimi's vehicle had been shot at by several armed men in a car, and that two suspects had been arrested after the attack.
Locals at the scene said Hashimi's car had its tyres shot out and crashed through a nearby garage in an effort to evade the gunmen.
Blood was still visible at the scene, as were bullet holes in the gate of a nearby house. Iraqi police sealed off the site and FBI officials were also at the scene.
Aqila al-Hashimi was due to go to
the UN in New York next week
Hashimi had been due to travel to the US this month as one of the members of the Iraqi delegation attending next week's United Nations General Assembly meeting.
She was one of three Governing Council members in an Iraqi delegation to the UN Security Council in July.
Some Iraqis have denounced the council for cooperating with Iraq's US-led administration.
Muhammad Baqir al-Hakim, head of a Shia Muslim party represented on the council, was killed in August in a car bomb attack in the city of Najaf.
US soldiers wounded
In north and central Iraq, five US soldiers were wounded in a spate of attacks on Saturday, with an explosion and an exchange of gunfire hitting the flashpoint town of Falluja.
Witnesses and the US military said rockets and bombs were used against occupation troops forces, extending a series of attacks from resistance forces since a new audiotape attributed to ousted president Saddam Hussein was released last Wednesday.
Falluja is at centre of resistance
to US-led occupation
Three US soldiers were reportedly wounded when rocket-propelled grenades (RPGs) were fired at their trucks in the northern Iraqi city of Mosul.
At around the same time, another US military truck came under RPG attack in another district of Mosul, said residents. But it was not clear if there were further casualties.
The attacks were launched shortly after an explosion was heard across Falluja, 50km west of Baghdad, at about 10:20 am (06:20 GMT). Gunfire erupted immediately after that attack.
The explosion occurred shortly after the main highway and a second access route, both linking the capital to Falluja, were reopened after being cut by hundreds of troops and vehicles entering the city's outer area.
Iraqis listen to latest message
reportedly by Saddam Hussein
Iraqi police rushed to the scene and said an oil tanker had been destroyed by the blast but the US military in Baghdad could not immediately confirm the latest strike in Falluja.
However, the military did confirm an additional two US troops from the 82nd Airborne Division had been injured on Friday at Ramadi, 110km west of the Iraqi capital.
Their convoy was attacked with an "improvised explosive device" and the wounded evacuated to a nearby military hospital.
Aljazeera correspondent in Tikrit reported US forces on Saturday arrested about 60 people from the village of Bu Ajil, east of Tikrit on the grounds that fighters from the village had attacked a US patrol.
The villagers said US forces had besieged the village for 20 hours. They accused them of confiscating their money and light weapons.
US forces did not comment on the raid.
Resistance attacks have killed 76 US soldiers since Washington declared combat over on 1 May. Iraqi police, and translators working for the US military, have also been targeted.