Saint Ouen is one of the 12 parishes. It is in the north west of the Island. It is the largest parish by surface area, covering 8,341 vergées.
It is reputed to be the most traditional of the parishes, being the farthest from Saint Helier and with much of the territory of the parish forming a peninsula. Its manor - the seat of the De Carteret family for over eight centuries - is the senior fief in the island, and the influence of that family has also been a factor in the parish's independent-minded approach to its affairs.
A number of the most influential writers of Jersey have been St Ouennais. George F Le Feuvre (1891 - 1984), who wrote under the pseudonym "George d'la Forge", was one of the most prolific authors of Jèrriais literature of the 20th century. Frank Le Maistre (1910-2002), compiler of the Dictionnaire Jersiais-Français (1966), did much to standardise the St Ouennais dialect of Jèrriais as a literary language. Edward Le Brocq (1877-1964) wrote a weekly newspaper column from 1946 to 1964 recounting the lives and opinions of two St Ouennais characters, Ph'lip and Merrienne.
The traditional nickname for St Ouennais is Gris Ventres (grey bellies) - a reference to the custom of men from the parish to wear jerseys of undyed wool, which distinguished them from men from other parishes who generally wore blue.
A number of prehistoric sites are located in St Ouen, including the dolmen des Monts Grantez, located at Le Chemin des Monts; the dolmen des Geonnais; and the prehistoric site at Le Pinacle, which also contains one of the very few identifiable Gallo-Roman sites to be seen in Jersey, the foundations of a fanum (small temple).
Helier de Carteret, the seigneur of the parish, received a charter from Queen Elizabeth I to colonise Sark with 40 families from the parish on condition that he maintain the island free of pirates. Sercquiais is therefore a very old offshoot of St Ouennais.
In the north west, the ruins of Grosnez Castle are a landmark which also features on the Jersey 50 pence coin. The Island's racecourse is also to be found at Les Landes.
Saint Ouen is twinned with:
- Coutances in France
Unlike the other parishes of Jersey, the subdivisions of this parish are not named vingtaines, but cueillettes (Jèrriais: tchilliettes). Vingteniers are still elected, however, in the cueillettes.
- Petite Cueillette
- Grande Cueillette
- Cueillette de Grantez
- Cueillette de Millais
- Cueillette de Vinchelez
- Cueillette de Léoville
St Ouen forms one electoral district and elects one Deputy.
The parish has a painting of Edward VII on display in the Parish Hall, featured in the Your Paintings project.