| Competition: | Hyundai Motors K2 League |
| Season: | 2004 |
| Winners: | Goyang Kookmin Bank (2nd title) |
| Best Player: | First stage: Kim Yoon-dong[1] Second stage: Kim Hae-gook[2] Playoff: Kim Dong-min[3] |
| League Topscorer: | Kim Jae-cheon (8 goals)[4] |
| Matches: | 92 |
| Total Goals: | 221 |
| Biggest Home Win: | HMD 4–0 Gangneung (28 August 2004) |
| Biggest Away Win: | Sangmu 1–5 HMD (30 May 2004) |
| Highest Scoring: | Hummel 3–3 Hallelujah (16 May 2004) HMD 4–2 Hummel (22 May 2004) Sangmu 1–5 HMD (30 May 2004) KHNP 3–3 Suwon (29 August 2004) |
| Longest Wins: | 8 matches |
| Longest Unbeaten: | 18 matches Hyundai Mipo Dockyard |
| Longest Winless: | 10 matches Gimpo Hallelujah |
| Longest Losses: | 6 matches Seosan Citizen |
| Prevseason: | 2003 |
| Nextseason: | 2005 |
The 2004 K2 League was the second season of the Korea National League. It was divided into two stages, and the winners of each stage qualified for the championship playoff.
----Goyang Kookmin Bank won 4–1 on aggregate.