Rhiannon is a moderately popular girls' name in England & Wales, ranking #167 in 2005 with 305 recorded births. The name reached its all-time peak in 1998 with 657 births ranking #83. Since 1996, the popularity has decreased by 53.4%. In 2005, approximately 1 in every 945 girls born was named Rhiannon. STABLE Recent data shows the name is currently stable.