Riayn \ri(a)-yn\ as a girl's name is a variant of Ryan (Irish, Gaelic), and the meaning of Riayn is "king".

The baby name Riayn sounds like Riann and Rian. Other similar baby names are Diann, Dian, Eiryn, Liann, Ray, Rayna, Raye, Rayne, Raya, Rain, Ravyn, Rivy, Ria, Rianon, Rianne, Rianna, Riane, Riana, Rhiann, Ryann, Robyn and Sian.