The defendants, who were arrested in March after the discovery of a weapons cache, admitted to being part of the Nigerian extremist group at a "public hearing" in the northern town of Maroua, said the report.
They had been charged with the illegal possession of firearms and ammunition and of plotting an insurrection.
"Each of the Boko Haram members (was) sentenced to between 10 and 20 years" in prison, said the report, adding that the sentences cannot be appealed.
The trial was reportedly the first of its kind in Cameroon where a large number of members of the radical group have been arrested in the north over the past weeks following attacks on police stations, as well as kidnappings and killings.
The armed movement is seeking to install an extremist Islamic state in Nigeria. It started its bloody insurgency in 2009.
More than 3,000 Nigerians fleeing Boko Haram attacks have taken refuge in the Cameroon town of Fotokol, according to a municipal official.
"We are worried about infiltrations" by the Islamists among the refugees, a police officer in the town said.