Khaled al-Johani was arrested last March in Riyadh on charge of supporting demonstrations, being present at the site of a planned protest, and talking to the foreign press "in a manner that harmed the reputation of the Kingdom," according to Amnesty.
The London-based human rights group released a statement late on Wednesday, condemning Johani’s trial earlier in the day as "utterly unwarranted."
The statement further urged Saudi authorities to release the jailed teacher "immediately and unconditionally.”
He "shouldn't be standing trial in any court for peacefully exercising his rights to freedom of expression and assembly," Amnesty's Middle East and North Africa Director Phillip Luther stated.
On March 11, 2011, the Saudi regime launched a massive clampdown to prevent a planned "Day of Rage" protests, demanding democratic reform in the Persian Gulf monarchy.
Johani was apparently the only protester who was able to reach the location of the planned rally and was arrested minutes after he talked to BBC Arabic about the lack of freedoms in Saudi Arabia, according to the statement.
Amnesty said the 42-year-old father of five, including a six-month old who was born during his detention, is being tried at the Specialized Criminal Court in Riyadh, a court established to deal with terrorism charges.
The statement said that Johani has so far been denied legal representation, though the judge during Wednesday's hearing said he would be allowed to appoint one "within a week."
Johani's trial will resume in April, it added.