Rhiannon is a distinctive girls' name in United States, ranking #740 in 2006 with 378 recorded births. The name reached its all-time peak in 1999 with 651 births ranking #424. Since 1996, the popularity has increased by 27.3%. In 2006, approximately 1 in every 5,029 girls born was named Rhiannon. STABLE Recent data shows the name is currently stable.