Yim Si-wan (임시완), born Im Ung-jae on December 1, 1988, in Busan, is a South Korean actor and singer. He made his debut in the music industry in 2010 as a member of the group ZE:A before gradually transitioning to acting, a field in which he has gained significant recognition.
He first gained attention in 2012 for playing the younger version of Heo Yeom in the historical drama Moon Embracing the Sun, a huge television hit. He followed that up with Man from the Equator, Standby and Waiting for Love. His career reached a new milestone in 2014 with Triangle, and above all Misaeng: Incomplete Life, where his portrayal of Jang Geu-rae—a young employee discovering the cutthroat world of corporate life—earned him several awards and turned the drama into a true cultural phenomenon in Korea.
After The King in Love In 2017, he returned from his military service with a much darker outlook on Strangers from Hell in 2019, playing Yoon Jong-woo opposite Lee Dong-wook. He then returned to romance in Run On in 2020, in which he plays the former sprinter Ki Seon-gyeom.
In 2022, he demonstrated his versatility with Trace and its second season, in which he plays the daring tax investigator Hwang Dong-joo, and then with the melancholic Summer Strike. The following year, his comedic transformation in Boyhood, in which he plays Jang Byeong-tae, a shy teenager mistaken for a formidable fighter, earned him a nomination for Best Actor at the Baeksang Arts Awards.
His international popularity grew even further when he joined Squid Game Season 2 in 2024, and then Squid Game Season 3 in 2025 as Lee Myeong-gi, player No. 333. He went on to play the lead role of Yun I-jun in Love in Disguise in 2026.
In film, he has also distinguished himself in The Attorney, The Merciless, Emergency Declaration, Unlocked, Road to Boston and Mantis, confirming a particularly diverse career spanning romance, thrillers, social dramas, and darker characters.
