Patrick Mahony, a Swiss-British national, was sentenced to six years by the Federal Criminal Court on Wednesday. The court found him guilty of fraud, criminal mismanagement and money laundering.
The verdict was the latest episode in the 1MDB affair, a complex tale of international corruption that has caught up a slew of financial institutions and individuals across the globe since allegations of wrongdoing first surfaced in 2015.
Mahony was convicted along with Swiss-Saudi Tarek Obaid, who was sentenced to seven years in prison. Obaid's lawyers have also said they would appeal.
Mahony's lawyers said the judgement was "shocking" and they would appeal against the court's decision.
"The judgment accuses our client of acts committed by various Malaysian individuals without ever examining what our client could have or might have known," said Laurent Baeriswyl, a lawyer for Mahony.
"We clearly demonstrated during the trial that none of the conditions of the crimes were fulfilled and we are confident that the court of appeal ... will take into account the overwhelming evidence that exonerates our client."
