- French commune.name
- Gaillon-sur-Montcient
- French commune.commune status
- Commune
- French commune.image
- Gaillon-sur-Montcient - mairie02.png
- French commune.caption
- The town hall in Gaillon-sur-Montcient
- French commune.arrondissement
- Mantes-la-Jolie
- French commune.canton
- Les Mureaux
- French commune.INSEE
- 78261
- French commune.postal code
- 78250
- French commune.mayor
- Marie-Christine Dubernard
- French commune.term
- 2022–2026
- French commune.intercommunality
- CU Grand Paris Seine et Oise
- French commune.elevation m
- 91
- French commune.elevation min m
- 22
- French commune.elevation max m
- 126
- French commune.area km2
- 4.83
