| Hertsön | |
| Map: | Sweden |
| Coordinates: | 65.5842°N 22.1995°W |
| Waterbody: | Bothnian Bay |
| Area Km2: | 73.42 |
| Country: | Sweden |
| Country Admin Divisions Title: | County |
| Country Admin Divisions: | Norrbotten |
| Country Admin Divisions Title 1: | Municipality |
| Country Admin Divisions 1: | Luleå |
Hertsön is a Swedish island in the Bothnian Bay, largely occupied by the eastern districts of the city of Luleå.
Due to post-glacial rebound, the islands Svartön, Mulön, Granön and Björkön have merged with the island. The size of the island is around 73.42 km², making it the twelfth largest island in Sweden.