Eskinder Nega and 23 others were found guilty last month.
They were accused of links with US-based opposition group Ginbot Seven, which Ethiopia considers a terrorist organisation.
Opposition member Andualem Arage was given a life sentence by the court, AFP news agency reports.
In May, Eskinder was awarded the prestigious Pen America's Freedom to Write annual prize for his work.
"The court has given due considerations to the charges and the sentences are appropriate," Reuters news agency quotes Judge Endeshaw Adane as saying.