Judge Aref Abdul-Razzaq al-Shahin made the announcement in Baghdad.
The court's decision must still be ratified by President Jalal Talabani and Iraq's two vice presidents.
The former Iraqi leader and two former aides were sentenced to death by hanging in November over the killings of 148 Shi'a from the town of Al-Dujayl, slain after Hussein escaped an assassination attempt there in 1982. The appeals court also upheld the death sentences of the two codefendants.
In another trial, Hussein and six codefendants are facing genocide charges related to a 1980s campaign against Kurdish civilians.