Rheannon is a distinctive girls' name in United States, ranking #12210 in 2006 with 9 recorded births. The name reached its all-time peak in 1999 with 20 births ranking #5384. Since 1996, the popularity has decreased by 18.2%. In 2006, approximately 1 in every 211,230 girls born was named Rheannon. FALLING Recent data shows the name is currently falling.