Lee joined K League club FC Seoul in 2021,[1][2] and made his professional debut on 21 April 2021.[3] He was considered one of the best centre-backs in South Korea while playing for Seoul.[4]
Midtjylland
On 28 August 2023, Lee signed with Danish Superliga club Midtjylland on a four-year contract for a fee reported to be around $1.5 million.[5][6] On 5 November, he made his debut in a 4–1 away win against Hvidovre, where he assisted the final goal.[7] On 25 February 2024, he scored his first professional goal in a 3–2 win over AGF. However, he made only three appearances in his first season at Midtjylland.[3]