| Country: | South Korea |
| Dates: | 17–31 October 1998 |
| Num Teams: | 4 |
| Champion Other: | Suwon Samsung Bluewings |
| Second Other: | Ulsan Hyundai Horang-i |
| Matches: | 5 |
| Goals: | 9 |
| Top Scorer: | 9 players |
| Prevseason: | 1996 |
| Nextseason: | 1999 |
The 1998 K League Championship was the fifth competition of the K League Championship, and was held to decide the 16th champions of the K League. It was contested between the top four clubs of the regular season. The first round was played as a single match between third place and fourth place of the regular season. The winners of the first round advanced to the semi-final, and played against runners-up of the regular season over two legs. The final progressed in the same way as the semi-final, and winners of the regular season qualified directly.
See main article: 1998 K League.
4–4 on aggregate. Ulsan Hyundai Horang-i won 4–1 on penalties.
Suwon Samsung Bluewings won 1–0 on aggregate.
See main article: 1998 K League.