Seol Young-woo was born on 5 December 1998 in Ulsan, South Korea. He developed through Ulsan Hyundai's youth pathway and the University of Ulsan, entering the senior side as a disciplined full-back who could play on either flank and rarely looked overwhelmed by tactical detail.
At Ulsan he became one of the K League's best full-backs, helping the club win domestic titles and contributing to its continental campaigns. His ability to play both right-back and left-back made him especially valuable, and he was named among the league's outstanding defenders before earning a move abroad.
In 2024 he joined Red Star Belgrade. By May 2026 he remains with the Serbian champions, having played domestic league matches and European fixtures, including Champions League-level nights. The move has given him a more physical defensive environment and a regular platform outside Korea.
Seol debuted for South Korea in 2023 and quickly became a serious national-team option, appearing at the 2023 AFC Asian Cup and through the 2026 World Cup qualifying cycle. His two-sided full-back profile is important for a squad that often changes shape within matches.
Around 1.80 m and right-footed, Seol is a balanced full-back with excellent stamina, defensive recovery and enough technique to support possession. He is often compared with Lee Yong for reliability, but his ability to switch flanks and carry the ball forward gives him a more modern, multi-role profile.