Rhiannon is a distinctive girls' name in United States, ranking #1440 in 2017 with 158 recorded births. The name reached its all-time peak in 1999 with 651 births ranking #424. Since 1996, the popularity has decreased by 46.8%. In 2017, approximately 1 in every 10,923 girls born was named Rhiannon. STABLE Recent data shows the name is currently stable.