Hanrahan is a surname with Irish origins shared among Irish people and descendants of Irish immigrants. Many famous people share this name as well. The name was originally spelled hAnnracháin and initially used in the Irish region of Leinster, where local nobles and kings with the name ruled. Variations include Hanradhan and Hanraghan. Many families of immigrants from Ireland of the Ó hAnnracháin family Anglicised their names to Hanrahan, and the name is somewhat common in the United States. Eochaidh, King of Leinster, an early monarch who fled to Scotland in exile in 540, was the first ruler to bear the surname. The name originates from Anradhán, diminutive of the Old Irish word ánradh, which translates to warrior.