Adilson dos Santos, shortly Adi or Adilson (born 12 May 1976), is a former Brazilian footballer, who last played as a left-back for South Korean K League Classic side FC Seoul. His good impression in Seoul was such that after retiring, he stayed as assistant manager at the club.

Adilson started his senior career playing with Apucarana Atlético Clube, and by 1998 he was estimated the best defender in Paraná State championship.

Next year, he moved to Serbian Red Star Belgrade where he played 11 matches in the First League of FR Yugoslavia during the 1998–99 season.

In 1999, he moved to Real Betis. but he did not make debut and moved to Sevilla FC. However, Sevilla did not have enough money to pay the transfer fee, so Real Betis lodged a complaint against Sevilla FC and he was not allowed to play for Sevilla FC. After the issue of the fee was resolved, he still did not play because he was deemed too young a player and the club was in the danger of regulation. He ended up playing on their B team.

In 2001, he moved to the giant club of China, Dalian Shide. He had succeeded in this club. He became the champion of Asia once and China 4 times also twice of Chinese FA Cup.

In March 2006, he moved to FC Seoul of K League Classic of South Korea ^[1]

He was winner of K-League Best XI in 2007, 2008 and 2010. He is now considered the best defender of the K-League after a collection of outstanding performances.

On 29 January 2014, he retired at FC Seoul and appointed as coach.^[2][3]