Kiernan is a distinctive girls' name in United States, ranking #10088 in 2012 with 11 recorded births. The name reached its all-time peak in 2002 with 34 births ranking #3851. Since 1996, the popularity has decreased by 50.0%. In 2012, approximately 1 in every 160,067 girls born was named Kiernan. FALLING Recent data shows the name is currently falling.