Kiernan is a distinctive girls' name in United States, ranking #10519 in 2025 with 9 recorded births. This places Kiernan in the bottom 39% of ranked US girls' names for the year. Its actual usage is classified as Rare. The name reached its all-time peak in 2002 with 34 births ranking #3851. Since 1996, the popularity has decreased by 59.1%. In 2025, approximately 1 in every 178,585 girls born was named Kiernan. FALLING Recent data shows the name is currently falling.