Lennix is a respelling of Lennox, a Scottish surname and district name from the Gaelic leamhnach, meaning "place of elms" or "elm grove". The x ending ties it to the current wave of names like Knox, Maddox and Phoenix, and the i spelling sets it apart from the more common Lennox. Lennix stood at number 11469 in 2000, reached number 2851 in 2022 and stands at number 2912 in 2025 with 43 births.