Rheannon is a distinctive girls' name in United States, ranking #7738 in 2002 with 14 recorded births. The name reached its all-time peak in 1999 with 20 births ranking #5384. Since 1996, the popularity has increased by 27.3%. In 2002, approximately 1 in every 128,344 girls born was named Rheannon. FALLING Recent data shows the name is currently falling.