The Persian Walnut was introduced into western and northern Europe very early, by Roman times or earlier, and to the Americas by the 17th century. It is cultivated extensively for its high-quality nuts, eaten both fresh and pressed for their richly flavoured oil; numerous cultivars have been selected for larger and thin-shelled nuts.
The wood is also of very high quality - similar to American Black Walnut - and is used to make furniture and rifle stocks.

The scientific name Juglans is from Latin jovis glans, "Jupiter's nut", and regia, "royal". It common name, Persian walnut, indicates its origins in Persia in southwest Asia; 'walnut' derives from the Germanic wal- for "foreign", recognising that it is not a nut native to northern Europe.
Other names include Walnut (which does not distinguish the tree from other species of Juglans), Common Walnut and English Walnut, the latter name possibly because English sailors were prominent in Juglans regia nut distribution at one time.

In Skopelos Greece, an island in the Aegean Sea, local legend suggests that whoever plants a walnut tree will die as soon as the tree can "see" the sea. This has not been proven as fact, however it might take some time to find a local arborist willing to take on the job of planting a walnut tree. Most planting is done by field rats.