Arlen is a name of uncertain origin, usually explained as an English surname or as a form of the Irish Arlan, "pledge" or "oath"; the Dutch surname Van Arlen is another possible source. It is best known in America through long-serving Pennsylvania senator Arlen Specter. The name has crept upward over the last decade, from number 2255 in 2015 to number 1587 in 2025, its best rank ever.