The 78-year-old Lai was convicted on Monday of two counts of foreign collusion and one count of seditious publication.
He is accused of collaborating with foreign forces within the framework of the controversial national security law that China imposed on Hong Kong in 2020.
The trial has received harsh criticism from the outside world. The Committee to Protect Journalists (CPJ) condemned the verdict, saying it underscored Hong Kong's contempt for press freedom.
This show trial is a shameful persecution,” said Beh Lih Yi, CPJ Asia-Pacific director.
Jimmy Lai founded the now-defunct pro-democracy and once often critical of Beijing newspaper Apple Daily. He is an outspoken critic of China's ruling Communist Party.
In 2019, Lai was sentenced to five years in prison for fraud. That sentence was also criticized.
Lai faces life imprisonment with the conviction.
Correction: In an earlier version of the text, Jimmy Lai's age was given incorrectly. He is 78 years old.
