Riannon is a distinctive girls' name in United States, ranking #11141 in 2003 with 9 recorded births. The name reached its all-time peak in 2000 with 14 births ranking #7494. Since 1996, the popularity has increased by 50.0%. In 2003, approximately 1 in every 203,006 girls born was named Riannon. RISING Recent data shows the name is currently rising.