Where the Ryan name comes from

Ryan is an Irish surname with several separate origins. The most common is a shortened form of O'Ryan, an anglicised spelling of the Gaelic Ó Riain, meaning descendant of Rian. It also stands for Mulryan or O'Mulryan, from the Gaelic Ó Maoilriain, meaning descendant of the follower of Rian. In rarer cases it anglicises Ó Ruadháin, the name behind Rowan, or Ó Sraitheáin, the name behind Strachan.

The meaning of the Old Irish name Rian itself is unknown, and scholars have discounted the suggestions that it comes from rían, meaning water or ocean, or from rí, meaning king. Rian, like Niall, seems to be so ancient that its meaning was lost before records began. In America the name sometimes has a different source altogether, as an adapted form of the German surname Rein.