Is the Russian olive related to the olive tree?

The Russian Olive is not used to make olives or olive oil. The Russian Olive, Elaeagnus angustifolia, is only remotely related to the olive tree. They share the same class, Magnoliopsida (Dicotyledons) but different order, species etc. There is evidence of cross-reactivity between olive, ash, privet, and Russian olive tree pollen allergens. (Annals of Allergy 69(6): 493-496) so if you are allergic to olive pollen don't plant Russian olive. Russian olive is a native of southern Europe and western Asia. It was introduced into the United States in the early 1900's and has now escaped cultivation and is extensively naturalized in 17 western states. According to the US forest service, once established, Russian-olive is hard to control and nearly impossible to eradicate. Control efforts have included mowing, cutting, burning, spraying, girdling, and bulldozing, most with limited success. It does produce a small fruit which is nutritious to deer, cattle, birds and rodents but when Russian olive displaces natural species the resultant habitat is generally considered inferior.