| Place name (English): | Onsøy |
| Place name (local language): | |
| Place name (alt. local language): | Deprecated: htmlspecialchars(): Passing null to parameter #1 ($string) of type string is deprecated in /var/www/geneapedia.org/public_html/include/place.php on line 504 |
| Place name (older spelling): | |
| Place name (other common spelling/language): | |
| Place type: | district |
| Is in the area of: | Fredrikstad |
| Note: |