Riannon is a distinctive girls' name in United States, ranking #11792 in 1997 with 7 recorded births. The name reached its all-time peak in 2000 with 14 births ranking #7494. Since 1996, the popularity has increased by 16.7%. In 1997, approximately 1 in every 248,666 girls born was named Riannon. RISING Recent data shows the name is currently rising.