| Official Name: | Karlsøy |
| Settlement Type: | Village |
| Pushpin Map: | Nordland#Norway |
| Pushpin Label Position: | left |
| Pushpin Map Caption: | Location in Nordland |
| Subdivision Type: | Country |
| Subdivision Name: | Norway |
| Subdivision Name1: | Northern Norway |
| Subdivision Name2: | Nordland |
| Subdivision Type3: | District |
| Subdivision Name3: | Salten |
| Subdivision Type4: | Municipality |
| Subdivision Name4: | Hamarøy |
| Utc Offset1: | +01:00 |
| Utc Offset1 Dst: | +02:00 |
| Postal Code Type: | Post Code |
| Postal Code: | 8260 Innhavet |
| Coordinates: | 68.0009°N 15.7655°W |
| Elevation M: | 5 |
| Elevation Footnotes: | [1] |
Karlsøy is a village in the municipality of Hamarøy in Nordland county, Norway. It is located on the southern coast of the island of Finnøya, along the Sagfjorden, about northwest of the village of Innhavet. Sagfjord Church is located in Karlsøy, serving the residents of this part of Hamarøy.