Ms Yingluck faces charges of dereliction of duty over corruption within the scheme, OAG spokesman Mr Kosolwat Inthujanyong told reporters.
If found guilty, she could face up to 10 years in prison.
Sources inside her former party suggested Ms Yingluck would not attend the hearing.
The former premier has already been impeached by the military-appointed legislature over the same charges and banned from politics for five years.
Ms Yingluck has denied all charges against her.
"I've never cheated anybody," she said during the impeachment proceedings.
She argued that the hearings were politically motivated and that she cannot be impeached as she was no longer in office.
Ms Yingluck was removed from office in May 2014 by the Constitutional Court after months of street demonstrations, including by farmers who had not been paid under the rice scheme.
The rest of her government was ousted later that month by a military coup that installed the current legislature and cabinet.