Declan has been given to about 58,950 people in the United States since 1880. It was most common in 2019, which makes it a current name.
Declan ranks 139th among American boys in 2025, with 2,587 born that year. Its best year was 2019, when 4,007 babies were given the name, ranking 95th. The typical living American called Declan is about 9 years old today. It is relatively most common in Wyoming, where it accounts for 0.32% 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.