Guilty verdicts along with sentences of 10 years in jail were given to 56 of the accused, Gulf News reported Tuesday.
Eight accused who were tried in absentia received 15-year jail sentences while five others received sentences ranging from three to seven years.
Prosecutors said the plotters belonged to the now-disbanded Al Islah Society believed affiliated with the Muslim Brotherhood.
The main goal of the organization, prosecutors said, "was to infiltrate the country's educational and social institutions."
Eighty-one of the defendants were male and 13 were female.