Tiernan is a distinctive boys' name in United States, ranking #3205 in 2022 with 38 recorded births. This places Tiernan in the top 22% of ranked US boys' names for the year. Its actual usage is classified as Rare. The name reached its all-time peak in 2007 with 86 births ranking #1738. Since 1996, the popularity has increased by 123.5%. In 2022, approximately 1 in every 45,905 boys born was named Tiernan. FALLING Recent data shows the name is currently falling.