Ulsan Hyundai was established in on 6 December 1983, as Hyundai Horang-i, with Horangi as its mascot. Their original franchise area was Incheon and Gyeonggi Province. They joined the professional K League from 1984 season. While they finished their debut season as 3rd place, the team's striker Baek Jong-chul became the K League Top Scorer, scoring 16 goals in 28 matches. They won their first professional trophy in 1986, winning the Professional Football Championship, which is the origin of Korean League Cup. From 1987 season, the club moved their franchise from Incheon and Gyeonggi Province to Gangwon Province. In the 1988 season, they finished the season as the runners-up in the league.
Beginning in the 1990 season, the club moved their franchise to Ulsan, where the headquarters of several branches of owner company Hyundai are located at, from Gangwon Province. Former South Korea's legendary striker Cha Bum-kun took the managerial position from the 1991 season, leading the club to the runners-up position in the league in his debut season. However, he failed to win any trophy and was replaced by Ko Jae-wook after the 1994 season. Under Ko Jae-wook, Ulsan won their second Korean League Cup trophy in 1995, which was his debut season as Ulsan manager. Ulsan won their first ever league title in 1996, beating Suwon Samsung Bluewings 3–2 aggregate in the championship playoffs. Ulsan then entered a long dry-spell in terms of league trophies, although they won their third Korean League Cup trophy in 1998, beating Bucheon SK 2–1 aggregate in the finals.
Two Kims Era (2000–2013)
Failure to add a major title for years did affect the team negatively. After the exodus of key players like Kim Hyun-seok and a terrible start in the 2000, manager Ko Jae-wook resigned in the middle of the season.
Ulsan appointed Kim Jung-nam, who had formerly managed South Korean national football team, as their next manager. They finished runners-up in 2002 and 2003, and started to emerge as a strong force. In 2005, with the return of two key players, Yoo Sang-chul and Lee Chun-soo, they qualified for the Championship Playoffs. In the play-off semi-final, they beat Seongnam Ilhwa 2–1, and in the final, they beat Incheon United 6–3 aggregate, with a hat-trick from Lee Chun-Soo in the first leg. They became the league champions for the second time in their history. The club also went on to win the A3 Champions Cup in 2006, which they participated as K-League champions. Although they lost their first match in the competition against JEF United Ichihara Chiba 2–3, they beat Dalian Shide 4–0 and Gamba Osaka 6–0 to clinch the trophy. Lee Chun-soo became the competition's top scorer, scoring 6 goals in 3 matches. They repeated the merciless attacks in the AFC Champions League that season, beating Al-Shabab 6–0 in the first leg of the quarter-finals. These overwhelming attacks they showed in the season gave Ulsan the nickname "Gangsters of Asia". Ulsan won the 2007 Korean League Cup, beating FC Seoul 2–1 in the final on 27 June 2007.
Manager Kim Jung-nam stepped down after the 2008 season. Kim Ho-kon, who had managed the South Korea national under-23 football team that reached the quarter-finals in the 2004 Summer Olympics was appointed as Ulsan's next manager. Kim Ho-kon did not enjoy Ulsan fans' full support for his first few seasons at the club, mainly because of his defensive tactical style and unsatisfying outcomes. 2011 season was a dramatic changeover; Ulsan won their fifth Korean League Cup, beating Busan IPark 3–2 in the final. Ulsan also finished the season as runners-up in the K League that season. Ulsan's unique style of having many players pushing forward in counterattacks earned them the nickname "Iron mace football". In 2012, the club won the AFC Champions League, defeating Al-Ahli 3–0 in the final on 10 November. In the run up to the final, Ulsan went on an unbeaten run throughout the 12 games of the competition, winning nine consecutive games and scoring 27 goals in the process.
