Cailyn has been given to about 5,554 people in the United States since 1880. It was most common in 2009, which makes it a millennial-parent name.
Its best year was 2009, when 401 babies were given the name, ranking 725th. The typical living American called Cailyn is about 18 years old today. It is relatively most common in Georgia, where it accounts for 0.01% 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.