From the Irish surname, Gaelic Ó Riain ‘descendant of Rian’. Ryan is associated with the film actor Ryan O'Neal (b. 1941) and is one of several names of Celtic origin that have become very popular throughout the English-speaking world since the 1990s. It is also now well established in North America as a girl's name.
German: from a medieval personal name, representing the Germanic clan name Nibelung ‘descendant of mist (or fog)’ (from a name cognate with German Nebel ‘mist’, ‘fog’). In Germanic mythology the Nibelungs were the doomed possessors of an immense hoard of treasure.