In a nationally televised verdict, the Seoul Central District Court convicted Park of bribery, extortion, abuse of power and other charges.

"It's inevitable that the defendant should be held strictly responsible for her crimes, if only to prevent the unfortunate event of [a president] abusing the power given by the people and causing chaos in state affairs," chief judge Kim Se-yun said.

Both Park and the prosecutors have one week to appeal. Park has maintained her innocence; prosecutors in February demanded a 30-year prison term.

The court said Park colluded with senior government officials to blacklist artists critical of Park's government to deny them state assistance programs. Park was also convicted of passing on presidential documents with sensitive information via one of her presidential aides.

The scandal had already led to the arrests, indictments and convictions of dozens of high-profile government officials and business leaders.

Hundreds of Park's supporters gathered near the southern Seoul court hours before the ruling, swinging South Korean and US flags under signs and banners that read, among other things, "Immediately release innocent president Park Geun-hye" and "Stop murderous political revenge".

Park's four years in office were marred by rising animosity with rival North Korea over its advancing nuclear program, a 2014 ferry disaster that killed more than 300 people, mostly teenagers on a school trip, and criticism that she curbed free speech and didn't manage things transparently.

AP