Rhiannon is a distinctive girls' name in United States, ranking #1426 in 2010 with 161 recorded births. The name reached its all-time peak in 1999 with 651 births ranking #424. Since 1996, the popularity has decreased by 45.8%. In 2010, approximately 1 in every 11,039 girls born was named Rhiannon. STABLE Recent data shows the name is currently stable.