In 1975, Sun Myung Moon, the owner of Tongil Group, wanted to found a professional football club in South Korea.

Tongil Group firstly considered to find the club in Honam provinces but there was objection from the local community.

[3] The club had chosen six players, including Ko Jeong-woon and signed Park Jong-hwan as the head coach.

[10] On 21 November 1999, Cheonan Ilhwa Chunma was crowned as the winners of the 1999 Korean FA Cup by winning the final 3–0 against Jeonbuk Hyundai Dinos at Jeju Stadium.

With Kim Hak-bum's management, the club bounced back to the forefront of South Korean football in style as they claimed their seventh league title in 2006, defeating Suwon Samsung Bluewings 3–1 on aggregate in the championship playoff final.

Seongnam reached the final of the 2007 K League Championship but were beaten 4–1 on aggregate by the Pohang Steelers, despite finishing in first place during the regular season.

[14] After months of confusion, the club appointed Kim Hak-bum, who previously led their golden age, as their manager.

The return turned out to be successful, as Seongnam not only escaped relegation but also won their third FA Cup trophy, beating FC Seoul in a penalty shoot-out.

The stadium earned the nickname "Tancheon Fortress" (탄천요새) in the 2000s due to the club's successful home record in the AFC Champions League.

The modern Seongnam Football Center, serving as the club's training ground, was completed in December 2021, built at a cost of 26 billion won.

On 22 August 1998, Cheonan Ilhwa Chunma had to finish the game against Jeonnam Dragons during the penalty shoot-out, after 1–1 draw in extra time.

On 13 November 2010, Seongnam beat Iranian club Zob Ahan FC 3–1 in the final of the 2010 AFC Champions League.

This was Seongnam's second AFC Champions League title and qualified them directly into the quarter-finals stage of the 2010 FIFA Club World Cup which they finished fourth.