Kacy has been given to about 6,047 people in the United States since 1880. It was most common in 1990, which makes it a Gen X and millennial name.
Its best year was 1990, when 222 babies were given the name, ranking 958th. The typical living American called Kacy is about 36 years old today.
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.