| Official Name: | Seskarö |
| Pushpin Map: | Sweden Norrbotten#Sweden |
| Pushpin Label Position: | left |
| Subdivision Type: | Country |
| Subdivision Name: | Sweden |
| Subdivision Type3: | Municipality |
| Subdivision Name3: | Haparanda Municipality |
| Subdivision Type2: | County |
| Subdivision Name2: | Norrbotten County |
| Subdivision Type1: | Province |
| Subdivision Name1: | Norrbotten |
| Area Footnotes: | [1] |
| Area Total Km2: | 1.62 |
| Population As Of: | 31 December 2010 |
| Population Total: | 491 |
| Population Density Km2: | 304 |
| Timezone: | CET |
| Utc Offset: | +1 |
| Timezone Dst: | CEST |
| Utc Offset Dst: | +2 |
| Coordinates: | 65.7386°N 23.7389°W |
Seskarö (Finnish: Seittenkaari) is a locality situated in Haparanda Municipality, Norrbotten County, Sweden with 491 inhabitants in 2010. It is located on the island with the same name which is about 20 km2 and situated in the Haparanda Archipelago. Since 1978, it has been connected to the mainland through a bridge, via some intermediate islands.