| Official Name: | Ostrožin |
| Native Name: | [1] |
| Settlement Type: | Village |
| Pushpin Map: | Croatia |
| Pushpin Map Caption: | Location of Ostrožin in Croatia |
| Pushpin Label Position: | bottom |
| Coordinates: | 45.4289°N 15.8558°W |
| Subdivision Type: | Country |
| Subdivision Name: |  Croatia |
| Subdivision Type1: | Region |
| Subdivision Name1: | Continental Croatia |
| Subdivision Type2: | County |
| Subdivision Name2: | Sisak-Moslavina County |
| Subdivision Type3: | Municipality |
| Subdivision Name3: | Gvozd |
| Unit Pref: | Metric |
| Area Footnotes: | [2] |
| Area Total Km2: | 17.7 |
| Elevation M: | 184 |
| Population As Of: | 2021 |
| Population Total: | 22 |
| Population Density Km2: | auto |
| Timezone: | CET |
| Timezone Dst: | CEST |
| Utc Offset: | +1 |
| Utc Offset Dst: | +2 |
| Postal Code Type: | Postal code |
| Postal Code: | 44410 |
| Area Code: | (+385) 44 |
Ostrožin (Serbian: Острожин)[1] is a village in central Croatia, in the municipality of Gvozd, Sisak-Moslavina County. It is connected by the D6 highway.
The Ostrožin Rulebook (Croatian: Ostrožinski pravilnik) was adopted on 14 December 1941 in Ostrožin.[3] Predating the Foča Regulations by more than a month, the Ostrožin Rulebook was the first legal act which regulated the new national authority in the liberated territories during the national liberation war of Yugoslavia.
According to the 2011 census, the village of Ostrožin has 32 inhabitants. This represents 8.14% of its pre-war population according to the 1991 census.
According to the 1991 census,[4] 94.91% of the village population were ethnic Serbs (373/393), 0.76% were ethnic Croats (3/393), 0.51% were Yugoslavs (2/393) and 3.82% were of other ethnic origin (15/393).