Rhiannon is a distinctive girls' name in United States, ranking #644 in 1997 with 346 recorded births. The name reached its all-time peak in 1999 with 651 births ranking #424. Since 1996, the popularity has increased by 16.5%. In 1997, approximately 1 in every 5,031 girls born was named Rhiannon. STABLE Recent data shows the name is currently stable.