| Hafslundsøy | |
| Coordinates: | 59.2894°N 11.1514°W |
| Map: | Norway |
| Location: | Glomma |
| Population: | 2,673 |
| Population As Of: | 2016 |
Hafslundsøy is a small island located in the middle of the river Glomma just outside Sarpsborg in Østfold, Norway. It had 2,673 inhabitants in 2016.