Shayden Thorne, 25, from Perth was held in Saudi Arabia since 2011 on charges, including supporting and encouraging terrorism, according to a ABC report.
Thorne had claimed that he admitted to the charges after he was tortured and should not have been considered at trial.
However, the judge had asked for evidence of the torture.
Thorne's lawyer Abdul Jalil Al-Khalidy told Thorne's family of the sentence after a hearing yesterday.
Jalil was unable to attend the hearing because he had been threatened with arrest, the report said.
With time already served, Thorne is expected to spend the next three years in prison.