Kay has been given to about 102,545 people in the United States since 1880. It was most common in 1942, which makes it a midcentury name.
Its best year was 1942, when 3,718 babies were given the name, ranking 75th. The typical living American called Kay is about 75 years old today. It is relatively most common in Texas, where it accounts for 0.00% 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.