In theory, Jalal Talabani, Iraq's head of state, must ratify all capital sentences. But he has previously said he would leave such a job to his vice-presidents because of his personal opposition to the death penalty.
Speaking to Al Jazeera on Tuesday, Hoshyar Zebari, Iraq's Kurdish foreign minister, said he hoped that the implementation of the sentence will bring the dark Saddam chapter of the country's history to a close and accelerate the process of reconciliation.
He said the suggestions of other governments such as Saudi Arabia and Egypt on Saddam's fate would be taken note of, but Iraq reserved the right to take its own decision as a sovereign state.
Iraqis celebrate verdict
Members of the country's Shia majority braved a strict curfew to celebrate the judgement with rowdy street parties, but some members of the once dominant Sunni community held protests and demanded Saddam's release.
The judge also upheld the death sentences against Barzan al-Tikriti, Saddam's half-brother, and Awad Ahmed al-Bandar, a former revolutionary court judge.
The US government said the decision was an "important milestone" for Iraqis.
"Today marks an important milestone in the Iraqi people's efforts to replace the rule of a tyrant with the rule of law," Scott Stanzel, a White House spokesman, said.
"Saddam Hussein has received due process and legal rights that he denied the Iraqi people for so long."
Saddam ruled Iraq between 1979 and March 2003, when he was overthrown by a US-led invasion force.
After his capture nine months later he was brought before the Iraqi High Tribunal in Baghdad to face trial.
Saddam and six co-defendants are also accused of killing 182,000 Kurds between 1987 and 1988, when government troops allegedly suppressed a Kurdish uprising by using artillery, air strikes, death camps and poison gas attacks.
They say that the so-called Anfal campaign was a legitimate counter-insurgency operation against Kurdish separatists at a time when Iraq was at war with Iran.
The Anfal trial has been adjourned until January 8.