Rheannon is a distinctive girls' name in United States, ranking #13872 in 2004 with 7 recorded births. The name reached its all-time peak in 1999 with 20 births ranking #5384. Since 1996, the popularity has decreased by 36.4%. In 2004, approximately 1 in every 262,303 girls born was named Rheannon. FALLING Recent data shows the name is currently falling.