Kiernan is a distinctive girls' name in United States, ranking #6391 in 2018 with 19 recorded births. The name reached its all-time peak in 2002 with 34 births ranking #3851. Since 1996, the popularity has decreased by 13.6%. In 2018, approximately 1 in every 89,496 girls born was named Kiernan. FALLING Recent data shows the name is currently falling.