Rhiannon is a distinctive girls' name in United States, ranking #744 in 2005 with 363 recorded births. The name reached its all-time peak in 1999 with 651 births ranking #424. Since 1996, the popularity has increased by 22.2%. In 2005, approximately 1 in every 5,090 girls born was named Rhiannon. STABLE Recent data shows the name is currently stable.