Variant of Arlene, possibly from Irish Gaelic meaning pledge or oath.
Arleen is a mid-century American variant of Arlene, a name whose roots reach into the mist of Celtic etymology. The most credible derivation connects it to the Irish and Gaelic element *arling* or to a feminization of the Old French name Arline, itself possibly related to the Germanic *adal* (noble) combined with a diminutive suffix. Some etymologists connect it more loosely to the Old High German *erla* (eagle) or to the Proto-Celtic root underlying names like Arlan and Arlen.
What is certain is that Arlene and its variants were essentially American inventions — names assembled from Celtic and Germanic raw materials in the late 19th century and refined into distinctly New World feminine forms. Arleen (and Arlene) surged in popularity during the 1920s through 1940s, riding the same cultural wave that lifted names like Marlene, Charlene, and Darlene — a fascination with feminine names ending in the liquid *-een* or *-ene* sounds that felt both romantic and modern. * for decades, and her glamour attached itself to the name's image.
Arleen with the double-e spelling is the slightly rarer, slightly softer variant, suggesting perhaps an Eastern European or immigrant influence in its orthography — a spelling that captures exactly how the name sounds when spoken warmly. By the 1970s, the -leen names had begun their decline as tastes shifted toward simpler, more international forms, but Arleen endures as a vintage gem, a name that conjures cigarette smoke curling above a piano bar, red lipstick, and a woman who knows exactly who she is.