Rhiannon is a moderately popular girls' name in England & Wales, ranking #363 in 2009 with 120 recorded births. The name reached its all-time peak in 1998 with 657 births ranking #83. Since 1996, the popularity has decreased by 81.7%. In 2009, approximately 1 in every 2,611 girls born was named Rhiannon. STABLE Recent data shows the name is currently stable.