Lee Soo-hyuk debuted as a model in 2006 and won the Best New Model award from the Korea Fashion Photographers Association the following year. He landed his first acting gig as the male lead in the 2010 independent teen fantasy romance film The Boy from Ipanema. In 2011, he appeared in several television dramas such as KBS2’s White Christmas and MBN’s What’s Up. In 2014, he joined the main casts of the tvN dramas High School King of Savvy and Valid Love. In 2015, he played an evil vampire in the MBC sageuk Scholar Who Walks the Night, which earned him the Best New Actor trophy at the MBC Drama Awards. In 2021, he reunited with Seo In-gook in the tvN fantasy romance Doom at Your Service and in the crime action film Pipeline.

Lee Soo-hyuk enlisted for his mandatory military service in August 2017 and was discharged in July 2019. He previously dated actress Kim Min-hee.