| Competition: | Druga HNL |
| Season: | 2004–05 |
| Winners: | Cibalia (North Division) Novalja (South Division) |
| Promoted: | Cibalia |
| Relegated: | Valpovka GOŠK Dubrovnik Uskok Klis |
| Prevseason: | 2003–04 |
| Nextseason: | 2005–06 |
The 2004–05 Druga HNL (also known as 2. HNL) season was the 14th season of Croatia's second level football since its establishment in 1992. The league was contested in two regional groups (North Division and South Division), with 12 clubs each.
| Club | City / Town | Stadium | Capacity | |
|---|---|---|---|---|
| Belišće | Belišće | Gradski stadion Belišće | 4,000 | |
| Bjelovar | Bjelovar | Gradski stadion Bjelovar | 4,000 | |
| Cibalia | Vinkovci | Stadion HNK Cibalia | 10,000 | |
| Čakovec | Čakovec | Stadion SRC Mladost | 8,000 | |
| Dilj | Vinkovci | Stadion NK Dilj | 3,000 | |
| Grafičar Vodovod | Osijek | Podgrađe | 4,500 | |
| Koprivnica | Koprivnica | Gradski stadion Koprivnica | 4,000 | |
| Marsonia | Slavonski Brod | Gradski Stadion uz Savu | 10,000 | |
| Metalac Osijek | Osijek | SC Bikara | 1,500 | |
| Slavonija Požega | Požega | Gradski stadion Požega | 4,000 | |
| Valpovka | Valpovo | Sportski park | 1,000 | |
| Vukovar '91 | Vukovar | Gradski stadion Borovo Naselje | 6,000 |
| Club | City / Town | Stadium | Capacity | |
|---|---|---|---|---|
| Croatia Sesvete | Sesvete | Stadion ŠRC Sesvete | 3,500 | |
| GOŠK Dubrovnik | Dubrovnik | Stadion Lapad | 7,000 | |
| Hrvatski Dragovoljac | Zagreb | Stadion NŠC Stjepan Spajić | 5,000 | |
| Imotski | Imotski | Stadion Gospin dolac | 4,000 | |
| Mosor | Žrnovnica | Stadion Pricviće | 3,000 | |
| Naftaš Ivanić Grad | Ivanić Grad | Sportski Park Zelenjak | 2,000 | |
| Novalja | Novalja | Cissa Strasko | 2,000 | |
| Pomorac | Kostrena | Stadion Žuknica | 3,500 | |
| Segesta | Sisak | Gradski stadion Sisak | 8,000 | |
| Solin Građa | Solin | Stadion pokraj Jadra | 4,000 | |
| Šibenik | Šibenik | Stadion Šubićevac | 8,000 | |
| Uskok Klis | Klis | Iza grada | 2,000 |
Cibalia and Novalja, winners of the North and South Division, qualified for a two-legged promotion play-off, which took place on 24 and 28 May 2005. Cibalia won the tie 5–1 on aggregate score, thereby earning promotion to the Prva HNL for the following season.
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However, Novalja had another chance for promotion, as the losing team from the promotion play-off played another two-legged tie against the 11th placed team of Prva HNL, Međimurje. Međimurje won 3–1 on aggregate.