Kiernan is a distinctive boys' name in United States, ranking #2295 in 1998 with 39 recorded births. The name reached its all-time peak in 2008 with 77 births ranking #1888. Since 1996, the popularity has decreased by 22.0%. In 1998, approximately 1 in every 49,008 boys born was named Kiernan. RISING Recent data shows the name is currently rising.