The court found that he had "negligently" failed to declare his income for six years.
Former Norwegian footballer John Carew has been sentenced to 14 months in prison for tax fraud.
The 43-year-old was found guilty of failing to declare around 12.8 million kroner (€1.2m) in income to Norwegian tax authorities between 2014 and 2019.
Carew had claimed he was living in the UK, but authorities found he had spent more than 183 days in Norway during that period.
He was also convicted of failing to declare a personal fortune of more than 300m kroner (€29m). In addition to the prison sentence, Carew was also fined 540,000 kroner (€52,000).
The Oslo court said on Wednesday that Norway's prison service would decide how Carew serves his sentence.
The former striker's lawyer Berit Reiss-Andersen has said they would read the verdict before a possible appeal.
"The court found that he acted with gross negligence, but not intentionally," Reiss-Andersen said, adding that Carew "wanted to make amends".
The former Norwegian international played for nine European clubs over 15 years, including Valencia, Roma, Lyon, and Aston Villa.
He also played 91 times for his country between 1998 and 2011 before embarking on an acting career.