She has been sentenced to five years in prison in absentia.
Yingluck failed to appear on August 25 as hundreds of her supporters waited outside Thailand's Supreme Court for the scheduled verdict.
At the time, a highly-placed source in Yingluck's Pheu Thai party said she had fled Thailand just before the hearing and was "safe and sound" in Dubai. A warrant was issued for her arrest.
Yingluck had faced up to 10 years in prison for her role in the rice-buying scheme, introduced in 2011, which pledged to pay farmers well above the market rate for their crops.
Critics say the program wasted large amounts of public funds trying to please rural voters, hurting exports and leaving the government with huge stockpiles of rice it couldn't sell.
Yingluck said the subsidy scheme was "beneficial for the farmers and the country" and claims it lost billions of dollars were wrong and motivated by political bias against her.
She has maintained a core group of followers since being ousted by a military coup in 2014.
Some were outside the court Wednesday, waiting to hear the verdict, though there were far fewer than the crowds seen spilling over the pavement onto the streets in August.
Then, large numbers of police had prepared for potential protests, depending on the outcome of the two-year trial.
Yingluck was barred from leaving Thailand without court approval in 2015, when the trial started. When she fled, the court confiscated her bail of 30 million baht ($900,000).
On Tuesday, the Thai junta's leader, Prime Minister Prayuth Chan-ocha, told reporters that he knew where Yingluck was, and would reveal her whereabouts after September 27, the day of the verdict.
When she was inaugurated in 2011, Yingluck became Thailand's first female prime minister and its youngest in over 60 years.
She followed her brother Thaksin Shinawatra to the role. Anti-government protesters, drawn mainly from Bangkok's middle class, royalist establishment, allege that Yingluck
was her brother's puppet, who was installed to carry on his work.
Thaksin was overthrown as Prime Minister in a military coup in 2006. He lives in Dubai and London in self-imposed exile to avoid corruption charges.
After the 2014 coup, Yingluck was impeached by Thailand's military-appointed National Legislative Assembly. The ruling barred her from political office for five years.
At the time, Yingluck said she had behaved with integrity and honesty during her time as prime minister.
Amid the outcry over the rice subsidy scandal, Yingluck was investigated by Thailand's National Anti-Corruption Commission (NACC) for the rice subsidy issue and put on trial. The trial lasted two years.