In 2025, 34 US boys were named Kiernan, making it the 3,409th most common boys’ name of the year, down 272 places from #3,137 in 2024. That is 5 fewer than the 39 boys named Kiernan in 2024. Its best rank for boys was #1,694, reached in 2000. The most boys given the name in a single year was 77, in 2008. For comparison, it was #2,943 in 2015 and unranked in 1950.
In 2025, 9 US girls were named Kiernan, making it the 10,519th most common girls’ name of the year, up 3,895 places from #14,414 in 2024. That is 3 more than the 6 girls named Kiernan in 2024. Its best rank for girls was #3,852, reached in 2002. That year also had the most girls given the name: 34. For comparison, it was #9,827 in 2015 and unranked in 1950.
Social Security card records list Kiernan in 53 years of the 146 from 1880 to 2025, starting in 1957 with 5 babies. In all, 2,448 US babies have been given the name, 28% of them girls and 72% boys. Its busiest decade was the 2000s, with 879 babies named Kiernan.
Over the 10 years from 2016 to 2025, 365 US boys were named Kiernan; the busiest of those years was 2017, with 54. In 2025 that was about 1 in 50,238 of the boys in SSA’s list for the year.
Rarer spellings such as Keirnan and Kiernen are summarised on this page.