Riannon is a distinctive girls' name in United States, ranking #9228 in 2001 with 11 recorded births. The name reached its all-time peak in 2000 with 14 births ranking #7494. Since 1996, the popularity has increased by 83.3%. In 2001, approximately 1 in every 163,687 girls born was named Riannon. RISING Recent data shows the name is currently rising.