Michael Naki (left) and Ruslan Leviev (right).
Prosecutors said the journalists, Ruslan Leviev and Michael Nacke, posted a video online last March containing information about the military that they knew to be false.
Nacke runs a YouTube channel with more than 700,000 subscribers, while Leviev founded the respected Conflict Intelligence Team (CIT), which investigates Russia's army.
Both Nacke and Leviet left Russia before they were charged in May. Prosecutors announced the sentence in a statement on Tuesday.
Russia has used the charges to silence high-profile government critics since launching the offensive in Ukraine last year.
Both men were earlier declared "foreign agents" -- a label with Soviet-era connotations used to stifle dissent.
CIT was branded an "undesirable organisation" in August, which criminalised its work and put staff members at risk of prosecution.