Park Geun-hye was also fined 18 billion won (€13.8 million) after being convicted on corruption charges
South Korea's former Park Geun-hye president has been found guilty of corruption and sentenced to 24 years in prison.
The Yonhap news agency reported a South Korean court convicted Ms Park of several counts of corruption - including bribery, coercion and abuse of power.
She was also fined 18 billion won (€13.8 million).
In comments quoted by Reuters, judge Kim Se-yoon said: "The defendant abused her presidential power entrusted by the people, and as a result, brought massive chaos to the order of state affairs and led to the impeachment of the president, which was unprecedented."
Park Geun-hye - who had been boycotting the trial - was not in court for the verdict, which was broadcast live.
Ms Park became South Korea's first ever female president when she took office in 2013.
She was impeached and arrested a year ago, amid a corruption scandal that rocked the country.
Her impeachment came after mass protests, which saw hundreds of thousands of people taking to the streets to demand she was removed from office.
She became the country's first democratically elected leader to be forced from office.
She had been accused of allowing her longtime friend Choi Soon-sil manipulate power from behind the scenes.
Ms Park apologised following the revelations, saying she "put too much faith in a personal relationship and didn't look carefully at what was happening".
However, the ousted president has denied any wrongdoing, and has indicated she will appeal her sentence.