Rhiannon is a distinctive girls' name in United States, ranking #1613 in 2014 with 134 recorded births. The name reached its all-time peak in 1999 with 651 births ranking #424. Since 1996, the popularity has decreased by 54.9%. In 2014, approximately 1 in every 13,328 girls born was named Rhiannon. STABLE Recent data shows the name is currently stable.