Rhiannon is a distinctive girls' name in United States, ranking #622 in 2004 with 439 recorded births. The name reached its all-time peak in 1999 with 651 births ranking #424. Since 1996, the popularity has increased by 47.8%. In 2004, approximately 1 in every 4,183 girls born was named Rhiannon. STABLE Recent data shows the name is currently stable.