Rhiannan is a distinctive girls' name in United States, ranking #9642 in 1997 with 9 recorded births. This places Rhiannan in the bottom 40% of ranked US girls' names for the year. Its actual usage is classified as Rare. The name reached its all-time peak in 1998 with 14 births ranking #7011. In 1997, approximately 1 in every 193,407 girls born was named Rhiannan. RISING Recent data shows the name is currently rising.