Kiernan is a distinctive girls' name in United States, ranking #8425 in 2011 with 14 recorded births. The name reached its all-time peak in 2002 with 34 births ranking #3851. Since 1996, the popularity has decreased by 36.4%. In 2011, approximately 1 in every 125,629 girls born was named Kiernan. FALLING Recent data shows the name is currently falling.