Walnut oil is a strongly yellow oil with characteristic walnut taste.

Walnut oil is oil extracted from walnuts, Juglans regia. The oil contains polyunsaturated fatty acids, monounsaturated fatty acids, and saturated fats 

A walnut is the edible seed of a drupe, and thus not a true botanical nut. It is commonly consumed as a nut. After fully ripening for its edible seed when the shell has been discarded, it is used as a garnish or a snack. Nuts of the eastern black walnut (Juglans nigra) and butternuts (Juglans cinerea) are less commonly consumed.

Walnuts are rounded, single-seeded stone fruits of the walnut tree commonly used for the meat after fully ripening. Following full ripening, the removal of the husk reveals the wrinkly walnut shell, which is usually commercially found in two segments (three or four-segment shells can also form). During the ripening process, the husk will become brittle and the shell hard. The shell encloses the kernel or meat, which is usually made up of two halves separated by a partition. The seed kernels – commonly available as shelled walnuts – are enclosed in a brown seed coat which contains antioxidants. The antioxidants protect the oil-rich seed from atmospheric oxygen, thereby preventing rancidity.