St Ouen is one of the twelve parishes of Jersey in the Channel Islands. It is around 8.8 kilometres (5.5 mi) north-west of St Helier. It has a population of 4,097. The parish is the largest parish by surface area, covering 8,525 vergées, and is located in part on a peninsula.

The parish is largely agricultural. There is no single centre as the church, parish hall and school are separated, however St Ouen's Village is the most significant settlement in the parish.

It is a highly distinct parish culturally. Being the farthest from St Helier, there are many differences between it and the rest of the island, for example having its own dialect of Jèrriais.

Its manor, Saint Ouen's 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 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).

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.