A breakdown of the sentences was not given but they are known to include jail terms, travel bans and house arrests.
Prince Nayef, the interior minister, announced in 2008 that 991 suspected fighters had been charged with participating in "terrorist attacks" over the past five years.
Human rights activists have criticised the kingdom for secretly holding the suspects and based on poorly defined charges. Rights groups also say that those convicted were denied fundamental rights including legal help in their defence.
However, last month Bandar al-Aiban, president of the official Saudi Human Rights Commission, said his group was monitoring the trials and that the defendants had received access to legal representation.