A variant of Elena or Helen, from Greek roots associated with light, brightness, or shining.
Elenna is an elaborated variant of Elena, which is itself the Italian, Spanish, and Slavic form of the ancient Greek Helénē. The etymology of Helénē is debated — it may derive from the Greek word for "torch" (selēnē), from a root meaning "shining" related to the sun god Helios, or from a pre-Greek substrate name whose meaning has been lost. Whatever its origin, the name entered Western consciousness most powerfully through Helen of Troy, whose legendary beauty sparked a decade of war in Homer's Iliad and Odyssey.
That single mythological figure gave the name a literary immortality unmatched by almost any other. R. Tolkien's invented geography — Númenor, the island kingdom of Men in his legendarium, was also called Elenna-nórë, meaning "land of the star" in Quenya, named because the Númenóreans navigated by the star Eärendil to find their new home.
This Tolkienian connection gives the spelling a quiet depth for readers of Middle-earth lore, though the name functions perfectly well without that context. Other literary echoes include Elena in Tolstoy, Elena Ferrante's modern Neapolitan Quartet, and Elena Gilbert of *The Vampire Diaries*. As a given name, Elenna feels like Elena with an added breath — slightly more formal, slightly more romantic, and unusual enough to distinguish its bearer in a classroom full of Elenas and Elenors. It has the structural elegance of classical naming traditions while wearing its origins lightly, making it equally at home in Italian, Slavic, Anglo-American, and fantasy-inflected naming contexts.