She added in a statement released through women’s rights organisation Womenlink: “Despite today’s ruling, I will continue to speak the truth to the very end.”
Womenlink blasted the decision, saying they were “outraged by a ruling that once again sexual violence in the theatre world”.
After being convicted, Yeong-su was sentenced to an eight-month prison term, suspended for two years, and ordered to complete 40 hours of attendance at a sexual violence treatment programme.
The prosecution had sought a one-year jail sentence.
The actor previously claimed he held the woman’s hand to guide her around a lake.
He added: “I apologised because [the person] said she wouldn’t make a fuss about it, but it doesn’t mean that I admit the charges,” he said.
But Judge Jeong Yeon-ju found the victim’s records of the assault and her claims were “consistent … and appear to be statements that cannot be made without actually experiencing them”.
The judge added: “What’s written in the victim’s diary, and the counselling report of the victim after the incident pretty much match the details of this case.”
Best known for his role as Oh Il-name in Netflix’s Squid Game, Yeong-su won South Korea’s first Golden Globe award in 2022 for his role in the show, in which poverty-hit contestants play childhood games with fatal consequences in a bid to win 45.6 billion won ($54.9 million).
He is seen as one of the greatest stage actors in South Korea, appearing in more than 200 stage productions since 1963 and winning a string of major awards.