Aileen is the Scottish and Irish form of Eileen, from the Gaelic Eibhlín, which came to Ireland with the Normans as Aveline and is usually read as "desired"; many families also link it to Helen, "shining light". It has been a steady American choice for over a century. Aileen ranked number 526 in 2000, peaked at number 454 in 2009 and has slipped to number 799 in 2025.