Prosecutors estimate he laundered 150 million euros in misappropriate funds in France.
The 50-year-old owns a six-storey, 107-million-euro mansion in an upscale part of Paris, complete with a hammam, a disco and gold-plated taps.
When investigators first raided the home, they hired trucks to haul away a fleet of Bugattis, Ferraris, a Rolls-Royce Phantom and other cars as evidence.
The fate of his residence, which was also seized by French authorities, remains unclear after Monday’s ruling, as Obiang’s lawyers have lodged an appeal with the International Court of Justice to claim the property should be offered the same protections as other diplomatic buildings.
A hearing is scheduled to take place in The Hague next week.
Obiang has said his money came from legitimate sources.
His lawyers accused France during his trial of “meddling in the affairs of a sovereign state”. Relations between the two nations have been strained over the case.
“It is another step in a legal marathon,” William Bourdon, a lawyer for one of the NGOs to have initiated the case, Transparency International, said of Monday’s ruling.
“It is a strong and powerful signal to those who believe that a culture of impunity is the indispensable means to organise and maintain a system of predation of public resources in Africa or elsewhere.”
Obiang could still lodge a final challenge to the Cour de Cassation, France’s highest appeals court for criminal cases.
He was agriculture and forestry minister before being promoted by his father to vice president, putting him in pole position to take over the leadership one day.
Africa’s only Spanish-speaking nation, Equatorial Guinea is the continent’s third-biggest oil producer but more than half of its 1.2 million population live below the poverty line.
It is regularly accused by human rights groups of corruption, repressive laws, extrajudicial killings and torture.
