Bainimarama led the Pacific island nation for 16 years until narrowly losing an election in December 2022 to a coalition of parties led by current Prime Minister Sitiveni Rabuka.
A former military chief, Bainimarama came to power in a 2006 coup and later won democratic elections in 2014 and 2018.
He was found guilty this month by the High Court of attempting to pervert the course of justice while he was prime minister by telling then police commissioner Sitiveni Qiliho to stay away from an investigation into the University of South Pacific, court documents show.
The High Court had overturned an earlier not guilty verdict delivered in 2023 by magistrate Seini Paumau in the Magistrates Court, and returned the case to the lower court for sentencing.
Paumau delivered a sentence on Thursday that cited Bainimarama's poor health and heart condition and granted him an absolute discharge.
Acting Director of Public Prosecutions John Rabuku filed an appeal against the sentence, with his office telling Reuters it was "manifestly lenient" and "erred in law".
In sentencing Bainimarama, Puamau said his conviction would not be registered, the statement said.
Bainimarama, who wished supporters "Happy Easter" outside the court, could not be reached for comment.
