Kiernan is a distinctive girls' name in United States, ranking #5028 in 2003 with 25 recorded births. The name reached its all-time peak in 2002 with 34 births ranking #3851. Since 1996, the popularity has increased by 13.6%. In 2003, approximately 1 in every 73,082 girls born was named Kiernan. FALLING Recent data shows the name is currently falling.