Killian has been given to about 16,834 people in the United States since 1880. It was most common in 2017, which makes it a current name.
Killian ranks 418th among American boys in 2025, with 785 born that year. Its best year was 2017, when 1,528 babies were given the name, ranking 248th. The typical living American called Killian is about 9 years old today. It is relatively most common in Vermont, where it accounts for 0.23% of births.
Source: US Social Security Administration, national and state name files, 2025 release, and the Office for National Statistics for England and Wales. Etymology researched and written by our editors. Living-population and median-age figures are our own estimates, described in the methodology.