| Finnish: Karhusaari | |
| Other Name: | Swedish: Björnsö |
| Settlement Type: | Helsinki Subdivision |
| Subdivision Type: | Country |
| Subdivision Name: |  Finland |
| Subdivision Type1: | Region |
| Subdivision Name1: | Uusimaa |
| Subdivision Type2: | Sub-region |
| Subdivision Name2: | Greater Helsinki |
| Subdivision Type3: | Municipality |
| Subdivision Name3: | Helsinki |
| Subdivision Type4: | District |
| Subdivision Name4: | Östersundom |
| Parts Type: | Subdivision regions |
| Parts Style: | para |
| Total Type: | |
| Population Total: | 381 |
| Postal Code Type: | Postal codes |
| Blank Name Sec1: | Subdivision number |
| Blank Info Sec1: | 58 |
| Blank1 Name Sec1: | Neighbouring subdivisions |
| Blank1 Info Sec1: | Östersundom, Talosaari, Sipoo |
Karhusaari (Finnish), Björnsö (Swedish) is a subdistrict of Helsinki, Finland.