Tongsun Park, 71, was found guilty in July by a New York jury in federal court of conspiring to act in the United States as an unregistered agent of the government of Iraq.,
Park admitted that he took more than $2.5 million from the government of Saddam Hussein to bribe senior UN officials.
His aim was to persuade them to ease economic sanctions that were imposed on Iraq after the 1991 Gulf War.
Güncelleme Tarihi: 20 Eylül 2018, 18:16
Park was also accused of assisting the former Iraqi regime in the creation of the UN oil-for-food programme.
Between 1996 and 2003 the scheme let the Iraqi government sell oil primarily to buy food and medicine for Iraqis to alleviate suffering caused by sanctions, but authorities say that by 2000, Saddam was demanding kickbacks from anyone he dealt with.
After serving his prison sentence, Park will have to spend three years on supervised release.
The court ordered Park to forfeit to the US government $1.2 million in profits he made from the scheme.
Michael Garcia, US attorney for the southern district of New York, said in a statement that the forfeited money was expected to be paid to the Development Fund for Iraq.
The court imposed the maximum sentence possible, under which Park was also fined $15,000 and agreed not to appeal.
The judge, Denny Chin, described it as a "harsh" sentence for a 71-year old man, but said that under the circumstances it was "appropriate".
"You acted out of greed, acted to profit out of what was a humanitarian programme," the judge said.
In the 1970s, Park was accused of being part of the "Koreagate" scandal in which agents of the Korean government were allegedly attempting to buy influence in the US Congress. Those charges were later dropped.