2018 FC Seoul season

The 2018 season was FC Seoul's 35th season in the K League 1.

Pre-season

 * In Murcia, Spain: From 6 January 2018 to 7 February 2018
 * In Kagoshima, Japan: From 14 February 2018 to 22 February 2018

Match reports and match highlights
Fixtures and Results at FC Seoul Official Website 

Attendance records

 * Season total attendance is K League 1, FA Cup, and AFC Champions League combined

Team squad
All players registered for the 2018 season are listed.

Out on loan and military service
Note: Where a player has not declared an international allegiance, nation is determined by place of birth.

※ In: Transferred from other teams in the middle of the season.

※ Out: Transferred to other teams in the middle of the season.

※ Discharged: Transferred from Sanjgu Sangmu or Ansan Mugunghwa for military service in the middle of the season (registered in 2019 season).

※ Conscripted: Transferred to Sangju Sangmu or Ansan Mugunghwa for military service after the end of the season.