Lee Jae-sung

Korea University (2011-2013) - Starred for the university's football team before dropping out to pursue a professional career in the K League.

Hakseong High School (2008-2010) - Developed his technical skills and tactical understanding while playing youth football in his hometown of Ulsan.

Lee Jae-sung began his professional career in 2014 when he joined K League 1 powerhouse Jeonbuk Hyundai Motors. He made an immediate impact as a rookie, utilizing his incredible stamina and vision to become a regular starter. During his highly successful stint in South Korea, he won four K League 1 titles, the 2016 AFC Champions League, and was named the K League 1 Most Valuable Player in 2017.

In July 2018, Lee made the bold leap to European football, signing with 2. Bundesliga club Holstein Kiel. He quickly became the creative hub of the team, orchestrating their attack and helping them reach the promotion playoffs and the DFB-Pokal semi-finals. His stellar performances in the German second tier attracted top-flight interest, leading to a free transfer to Bundesliga side 1. FSV Mainz 05 in 2021.

At Mainz, Lee established himself as a reliable and hard-working attacking midfielder in one of the world's most demanding leagues. He consistently logged significant minutes, known for his off-the-ball movement and crucial interventions. In April 2026, he suffered a left big toe fracture that threatened his season, but he miraculously returned to the pitch just weeks later in May, providing a massive boost to the squad.

Internationally, Lee has been a cornerstone of the South Korea national team since 2015. He played pivotal roles in both the 2018 and 2022 FIFA World Cups, helping the team advance to the knockout stages in Qatar. In October 2025, he earned his prestigious 100th international cap in a match against Brazil, joining an elite group of Korean footballers.

As a highly respected veteran, Lee's swift recovery in May 2026 was celebrated as a massive positive for head coach Hong Myung-bo. Named to the 2026 FIFA World Cup squad, Lee is poised to provide essential tactical balance and leadership in the midfield as South Korea competes in North America.

Lee Jae-sung was born and raised in Ulsan, a major industrial city with a rich footballing tradition. He grew up in a supportive family environment; his older brother, Lee Jae-hyuk, is a certified sports agent who currently manages his professional affairs and contract negotiations through SJ Sports. This strong sibling partnership has successfully guided his steady transition from the K League to the Bundesliga.

Off the pitch, Lee is famously known for his unselfish, team-first mentality. He is often described by managers as the ultimate professional, willing to sacrifice personal glory for the tactical success of the squad. He avoids flashy controversies and maintains a quiet lifestyle in Germany, focusing entirely on maintaining his physical condition for top-flight football.

As of 2026, Lee remains single. He occasionally writes columns and shares insights about his experiences playing in Europe, offering a thoughtful perspective on the mental and physical demands of professional football. As he approaches what could be his final World Cup, he has openly expressed a deep desire to leave a lasting, memorable mark on the international stage.