FC Seoul

Founding and early years (1983–1989)

FC Seoul was officially announced on 18 August as the new club and founded on 22 December 1983, and started out in 1984 as Lucky-Goldstar Football Club, owned and financially supported by the Lucky-Goldstar Group (later renamed the LG Group), with the Chungcheong Province its franchise and Hwangso (meaning bull) as its mascot.

In order to launch the professional football club, Lucky-Goldstar Group had a preparation period from 1982 and demanded that the original franchise should be Seoul. In the 1984 season, the club finished seventh out of the eight clubs. The club fared better in the 1985 season when they won the championship with the help of Thailand national football team player Piyapong Pue-on, who was the top scorer, as well as the top assistor.

Moving to Seoul and then to Anyang (1990–2003)

From the beginning of 1988, Lucky-Goldstar Hwangso pushed forward a relocation to Seoul At the end of the 1989 season, the Korea Professional Football League (renamed as the K League in 1998), worried about the financial stability of the clubs, invited a number of clubs to play in Seoul. Thus, the Lucky-Goldstar Hwangso, which had always wanted to be based in the capital, moved to Seoul Stadium (Currently Dongdaemun Stadium) in Seoul at the end of 1989. The club finished first season in Seoul as champions. The club changed its name to LG Cheetahs in 1991 to mirror the LG Twins, a professional baseball team also owned by LG Group. After several seasons in Seoul, the club was forced to move in 1996, as part of the K League's decentralization policy. This policy was carried out to stimulate the growth of football in the provinces. In addition, in 1995, Korea was bidding to host the 2002 FIFA World Cup. This warranted the construction of a soccer-specific stadium in Seoul. The three clubs based in Seoul – LG Cheetahs, Ilhwa Chunma, and Yukong Elephants did not want to recognize the decentralization policy. Ultimately, it proved necessary for the Korean government to issue an eviction order to the disaffected clubs. However, the government did guarantee if the clubs built a soccer-specific stadium in Seoul, the clubs could have a Seoul franchise and return to Seoul.

As a result, 3 clubs were evicted from Seoul to other cities. This entailed the move of the LG Cheetahs to the Anyang Sports Complex in the city of Anyang, a satellite city of Seoul, 21 km away. The club was now known as the Anyang LG Cheetahs. In the upcoming years, a solid base of supporters was formed, and it established a strong league rivalry with the Suwon Samsung Bluewings. This rivalry was partly fueled by the fact that LG Group and Samsung Group, which owned the Suwon club, were also considered rivals in the business world, especially in electronics. The club continued to grow and in 2000, they won their third Championship, behind the firepower of striker Choi Yong-Soo.

Return to Seoul and renaming to FC Seoul (2004–2006)

For the 2002 FIFA World Cup in South Korea and Japan, ten brand new stadiums of World Cup standards were built in South Korea. After the World Cup, the Korean World Cup Organizing Committee and the KFA actively supported the move of regional K League clubs into the new stadia. This was designed to avoid or at least minimize any financial losses through having to maintain a stadium in playing condition without regular income. However, due to the previous decision by the K League to exclude any member club from being based in Seoul, Seoul World Cup Stadium remained vacant, except as a host of some international friendlies. Thus, the city government of Seoul and the KFA both actively sought for a K League club to play at the stadium to take on the cost of maintaining the stadium. Initially, it was intended to create a new club, but when it later transpired that any club playing in Seoul World Cup Stadium would have to pay partially for the construction fees of the stadium, this would have placed an unreasonable burden on a fledgling club. Thus, the KFA tried to lure one of the current clubs to Seoul. The Anyang LG Cheetahs, with the financial backing of the LG Group, who not only viewed the move back to Seoul as a way to increase its advertising presence, but had the right to come back to Seoul because it had its franchise moved by force in 1996, as part of the K League's decentralization policy. Anyang LG announced in February 2004 that it would pay the share of the construction fees (which turned out to be 15 billion won, or at that time 15 million USD). This proposed move provoked a significant amount of controversy from the Korean football fans as KFA and K League failed to launch a new football club based in Seoul due to a high Seoul franchise fee. Regardless, KFA and K League ultimately permitted relocation of Anyang LG Cheetahs.

Şenol Güneş years (2007–2009)

Şenol Güneş managed FC Seoul for a three-year period starting on December 8, 2006. The club started the 2007 season with three consecutive wins and a draw, including a 4–1 win over arch rivals Suwon Samsung Bluewings in the Super Match. However, FC Seoul failed to qualify for the play-off phase of the season, but the club succeeded in getting into the final of the 2007 Korean League Cup. Before the next season, Park Chu-young, the ace of FC Seoul at that time, was transferred to Ligue 1 club Monaco. FC Seoul finished in a second-place in the K League regular season, and progressed to the play-offs. FC Seoul defeated Ulsan Hyundai in the play-off semi-final but was defeated by Suwon Samsung Bluewings in the final. Despite the loss, the club still qualified for the 2009 AFC Champions League. During the season, Dejan Damjanović scored 15 goals.

FC Seoul's 2009 AFC Champions League campaign began with a 2–1 win over Indonesian side Sriwijaya FC. In the next three games, FC Seoul obtained only one point in the matches against Gamba Osaka and Shandong Luneng. However, Seoul then defeated the title holders Gamba Osaka and qualified to the round of 16 after Sriwijaya's unexpected victory over Shandong Luneng. On June 24, 2009, FC Seoul beat Kashima Antlers 5–4 after penalties after a 0–0 draw in the round of 16 clash and advanced to the quarter-finals, but were beaten 4–3 on aggregate by Qatari club Umm Salal. FC Seoul's appearance in the AFC Champions League was its first since the Asian Club Championship era.

The Şenol Güneş era ended on November 25, 2009, with the manager returning to Trabzonspor.

K League and League Cup "double" (2010)

FC Seoul appointed Nelo Vingada as manager on December 14, 2009. Vingada won the K League and League Cup with FC Seoul. FC Seoul had 20 wins, 2 draws, and 6 defeats in the domestic league under Vingada's management.

FC Seoul recorded an attendance of 60,747 against Seongnam Ilhwa on May 5, 2010 at Seoul World Cup Stadium, which is the highest single-game attendance record in South Korean professional sports history. FC Seoul also recorded the single season (League, K League Championship, and League Cup) highest total attendance record – 546,397, and the single regular & post season (League and K League Championship) highest average attendance record of 32,576.

On August 25, 2010, FC Seoul beat Jeonbuk Hyundai Motors 3–0 to become the 2010 League Cup winners. FC Seoul were also crowned K League champions by defeating Jeju United 4–3 on aggregate in the K League Championship final, thus achieving their first "double" in the club's history. The crowd of 56,769 in the second leg also set the record of the highest attendance in K League Championship history.

On December 13, 2010, FC Seoul wanted to extend Vingada's one-year contract but FC Seoul and Vingada could not come to an agreement over the salary conditions, resulting in Vingada returning to Portugal.

AFC Champions League final and the sixth K League title (2011–2016)

FC Seoul's former player Choi Yong-soo was hired to manage the club in 2012, after previously serving as the assistant manager and caretaker for the club in 2011. In 2013, FC Seoul lost the AFC Champions League Final on away goals rule against Chinese side Guangzhou Evergrande. The AFC Champions League campaign has earned Choi Yong-soo the 2013 AFC Coach of the Year award, becoming the second South Korean in succession to win the individual accolade following the previous year's winner Kim Ho-kon. Choi left the club in June 2016.

On June 21, 2016, FC Seoul appointed Hwang Sun-hong as their eleventh manager in the club's history. On November 6, 2016, FC Seoul won their sixth K League title after defeating Jeonbuk Hyundai Motors 1–0 in the final round of the season.

A period of oscillation (2017–present)

Hwang Sun-hong resigned on April 30, 2018. In the 2018 season, FC Seoul finished in eleventh place and had to play the K League promotion-relegation playoffs for the first time in their history. In the playoffs, they defeated Busan IPark 4–2 on aggregate, thus staying in the top flight.

On October 11, 2018, Choi Yong-soo was appointed as the twelfth manager in the club's history, having previously managed the club between 2011 and 2016.

During the 2020 season, FC Seoul lost five consecutive games for the first time in 22 years. Following a new departure by Choi Yong-soo, three different caretakers took turns managing the team, with Park Hyuk-soon replacing Kim Ho-young after just a month and guiding the team to the end of the K League season, which they finished in ninth place, before being substituted by Lee Won-jun; under his management, the team made a promising start in the group stage of the 2020 AFC Champions League, even obtaining a 5–0 victory against Thai outfit Chiangrai United, but then proceeded to lose all of their last three matches, thus being eliminated from the tournament. A difficult season was made even more devastating by the death of defender Kim Nam-chun on October 30, 2020, just a day before their last K League 1 fixture against Incheon United.