Rhiannon is a distinctive girls' name in United States, ranking #1452 in 2011 with 156 recorded births. The name reached its all-time peak in 1999 with 651 births ranking #424. Since 1996, the popularity has decreased by 47.5%. In 2011, approximately 1 in every 11,274 girls born was named Rhiannon. STABLE Recent data shows the name is currently stable.