| Competition: | Druga HNL |
| Season: | 2008–09 |
| Winners: | Istra 1961 |
| Promoted: | Istra 1961 Karlovac Lokomotiva Međimurje |
| Relegated: | Trogir |
| League Topscorer: | Marijan Vuka (19) |
| Matches: | 240 |
| Total Goals: | 612 |
| Prevseason: | 2007–08 |
| Nextseason: | 2009–10 |
The 2008–09 Druga HNL (also known as 2. HNL) season was the 18th season of Croatia's second level football since its establishment in 1992. Croatia Sesvete were league champions and were promoted to Prva HNL at the end of the previous season.
The league featured 16 clubs, playing in a double round robin league system. The season started on 23 August 2008 and ended on 30 May 2009.
The following clubs have been promoted or relegated at the end of the 2007–08 season:
Promoted to 1. HNL
Relegated to 3. HNL
Relegated from 1. HNL
Promoted from 3. HNL
In a two-legged promotion/relegation playoff between Inter Zaprešić (as 11th placed 1. HNL team) and Hrvatski Dragovoljac (as 2. HNL runners-up), the former kept their Prva HNL status by beating Hrvatski Dragovoljac with 2–0 on aggregate (2–0, 0–0).
| Club | City | Stadium | 2007–08 result | Capacity | |
|---|---|---|---|---|---|
| Hrvatski Dragovoljac | Zagreb | 2nd in 2.HNL | 5,000 | ||
| Imotski | Imotski | Gospin dolac | 10th in 2.HNL | 4,000 | |
| Istra 1961 | Pula | Veruda | 3rd in 2.HNL | 3,500 | |
| Junak Sinj | Sinj | Gradski stadion Sinj | 3rd in 3.HNL South | 3,096 | |
| Karlovac | Karlovac | Branko Čavlović-Čavlek | 1st in 3.HNL West | 8,000 | |
| Lokomotiva | Zagreb | ŠRC Hitrec-Kacijan | 2nd in 3.HNL West | 1,000 | |
| Međimurje | Čakovec | Stadion SRC Mladost | 8,000 | ||
| Moslavina | Kutina | Gradski stadion u Kutini | 9th in 2.HNL | 2,000 | |
| Mosor | Žrnovnica | Stadion Pricviće | 11th in 2.HNL | 2,000 | |
| Pomorac | Kostrena | Stadion Žuknica | 4th in 2.HNL | 3,000 | |
| Segesta | Sisak | Gradski stadion Sisak | 7th in 2.HNL | 8,000 | |
| Slavonac CO | Stari Perkovci | Igralište Slavonca | 6th in 2.HNL | 1,000 | |
| Solin | Solin | Stadion pokraj Jadra | 12th in 2.HNL | 4,000 | |
| Suhopolje | Suhopolje | Stadion Park | 1st in 3.HNL East | 8,000 | |
| Trogir | Trogir | Gradski stadion Sinj | 8th in 2.HNL | 3,096 | |
| Vinogradar | Jastrebarsko | Stadion Mladina | 5th in 2.HNL | 2,000 |
The top scorers in the 2008–09 Druga HNL season were:[3]
| width=40 | Rank | width=180 | Name | width=130 | Club | width=50 | Goals | width=50 | Apps | width=50 | Minutes played |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 1 | Marijan Vuka | Međimurje | 19 | 27 | 2072 | ||||||
| 2 | Denis Ljuta | Solin | 13 | 28 | 2291 | ||||||
| Romano Obilinović | Imotski | 13 | 28 | 2452 | |||||||
| 4 | Zoran Zekić | Segesta, Moslavina | 11 | 24 | 1729 | ||||||
 Bojan Golubović | Slavonac CO | 11 | 24 | 1833 | |||||||
 Pinheiro | Vinogradar | 11 | 25 | 2090 | |||||||
| Ivica Žuljević | Međimurje | 11 | 29 | 2451 | |||||||
| 8 | Ivan Lišnić | Karlovac | 10 | 18 | 1301 | ||||||
| 9 | Eliomar | Međimurje | 9 | 24 | 1964 | ||||||
| Hrvoje Mišić | Slavonac CO | 9 | 28 | 2396 |