Before the execution, the Iraqi government readied all the necessary documents, including a "red card" -- an execution order introduced during Saddam's dictatorship. In addition, a Sunni cleric arrived at the heavily fortified Green Zone in Baghdad to hear any final admissions from the condemned former leader.
Saddam held a Quran as he was led to the gallows, and refused to wear a hood during the execution, reported the Associated Press.
Afterward, state television showed a man identified as Saddam lying on a stretcher, covered in a white shroud with what appeared to be bloodstains. His eyes were closed.
In Baghdad's Shiite enclave of Sadr City, word of Saddam's death prompted hundreds of people to dance in the streets, while others fired guns in the air in celebration.
President Bush issued a statement, reading in part, "Saddam Hussein's execution comes at the end of a difficult year for the Iraqi people and for our troops. Bringing Saddam Hussein to justice will not end the violence in Iraq, but it is an important milestone on Iraq's course to becoming a democracy that can govern, sustain, and defend itself, and be an ally in the war on terror."
Within hours of Saddam's execution, a bomb planted aboard a minibus exploded in a fish market south of Baghdad, killing 31 people.
Some Arabs predicted Saddam's hanging, particularly on the Muslim feast of Eid al-Adha, would worsen violence in Iraq.
"I don't have any sorrow or compassion for the man, but the timing is very stupid and Muslims will think this was done to provoke their feelings," said Ehab Abdel-Hamid, 30, a novelist and senior editor at Cairo's independent al-Dostour newspaper, reported Reuters.
The carrying out of Saddam's death sentence came after much confusion about when it would occur. An Iraqi appeals court on Dec. 26 upheld a previous ruling that Saddam and two of his top associates, Barzan Ibrahim al-Tikriti and Awad al-Bandar, be put to "death by hanging" for the killing of the Shiites. Those killed in the massacre had been detained after an attempt to assassinate Hussein.
The execution followed a last-ditch appeal by Saddam's lawyers to a U.S. court. Saddam's attorneys argued that, because the former Iraqi president also faced a civil lawsuit in Washington, he had rights as a civil defendant that would be violated if he is executed. He has not received notice of those rights and the consequences that the lawsuit would have on his estate, his attorneys said.
"Petitioner Hussein's application for immediate, temporary stay of execution is denied," U.S. District Judge Colleen Kollar-Kotelly said, according to the AP.
The Iraqi appeals court had set a deadline of 30 days for Saddam's execution when it upheld Saddam's sentence, but in the hours before the hanging, it was unclear if Iraqi officials had to approve the quickened death sentence.
The appeals court ruling upheld a Nov. 5 unanimous verdict in which Saddam, al-Tikriti and al-Bandar were sentenced to "death by hanging" for the killing in Dujail. Four other defendants were sentenced to prison terms ranging from 15 years to life; an eighth was acquitted.
Saddam reportedly had prepared for his execution by giving a copy of his will to two of his half brothers who came to his cell on Thursday.
His daughter, Raghd, exiled in Jordan, "is asking that his body be buried in Yemen temporarily until Iraq is liberated and it can be reburied in Iraq," a source close to the family told Reuters ahead of the execution.
The deposed leader also had been standing trial in another case known as the Anfal campaign, in which chemical weapons were used to wipe out 180,000 Kurds in the 1980s.
U.S. forces in Iraq remained on edge in case the former leader's death sparked renewed violence.
"U.S. forces in Iraq are obviously at a high state of alert anytime because of the environment that they operate in and because of the current security situation," Defense Department spokesman Bryan Whitman said.
The AP reported that U.S. authorities maintained physical custody of Saddam until the end to prevent him from being humiliated before his execution and possibly mutilated afterward, as has happened to other deposed Iraqi leaders.
Saddam's lawyers issued a statement on Friday calling on "everybody to do everything to stop this unfair execution."
But Iraqi Prime Minister Nouri al-Maliki said opposing Saddam's execution was an insult to his victims. "Our respect for human rights requires us to execute him, and there will be no review or delay in carrying out the sentence," he said, according to the AP.
Saddam had been in U.S. custody since he was captured in December 2003.