Rhiannon is a moderately popular girls' name in England & Wales, ranking #295 in 2008 with 159 recorded births. The name reached its all-time peak in 1998 with 657 births ranking #83. Since 1996, the popularity has decreased by 75.7%. In 2008, approximately 1 in every 1,986 girls born was named Rhiannon. STABLE Recent data shows the name is currently stable.