Girls' name · peaked in 1939
Kay name popularity since 1925
97,574 babies born in the US from 1925 to 2025 were named Kay (96.7% girls, 3.3% boys). Half of them were born in 1948 or earlier, so the typical Kay is about 78 years old in 2026. Kay peaked in 1939 as the #76 name for girls, and it was outside the top 1,000 in 2025.
Key facts
- US babies since 1925
- 97,574
- Named Kay, 1925–2025
- In 2025
- Not top 1,000
- #3,946 for girls in 2025
- Girls / boys
- 96.7% girls
- 94,358 girls · 3,216 boys
- Most popular in
- South Dakota
- 3.41× its national share
Peak year is the year Kay made up the largest share of US girls, in records going back to 1880. Typical age is based on births from 1925 on, not on who is living today.
Kay births per year, 1925–2025
The biggest year by count was 1942. Measured as a share of all babies, Kay peaked in 1939.
- Fastest rise: Between 1929 and 1934, Kay became 7× more common.
- Steepest fall: Between 1967 and 1972, its share of baby girls fell by 62%, from 1 in 2,320 to 1 in 6,060.
Shaded on the chart. Both compare Kay's share of all US girls five years apart, counting only years with at least 100 babies named Kay.
Decade by decade
Babies named Kay in each decade, and its rank among girls' names in the middle year of the decade (1935, 1945 … 2025).
| Decade | Girls | Boys | Rank |
|---|---|---|---|
| 1925–29 | 1,180 | 410 | – |
| 1930s | 17,301 | 1,306 | #134 |
| 1940s | 32,654 | 725 | #91 |
| 1950s | 24,645 | 321 | #157 |
| 1960s | 12,390 | 164 | #270 |
| 1970s | 2,517 | 64 | #720 |
| 1980s | 1,409 | 55 | #1,063 |
| 1990s | 869 | 47 | #1,768 |
| 2000s | 635 | 18 | #2,746 |
| 2010s | 504 | 40 | #3,632 |
| 2020–25 | 254 | 66 | #3,946 |
Ranks count every name given to at least 5 girls that year, so they can go past 1,000.
Generation fingerprint
47.7% of babies named Kay from 1925 to 2025 were born in the Baby Boom years (1946–1964). The full split by generation:
Where Kay is most popular
The index compares Kay's share of babies in each state with its share nationwide, 1925–2025 (1.50× = 50% more common). States with at least 300 babies named Kay.
| State | Index | Babies |
|---|---|---|
| South Dakota | 3.41× | 1,012 |
| Iowa | 2.81× | 3,329 |
| Wisconsin | 2.68× | 4,921 |
| Nebraska | 2.64× | 1,724 |
| North Dakota | 2.58× | 757 |
Names with a similar story
Of the other 1999 names on this site, these six had the share of babies closest in shape to Kay's from 1925 to 2025, however common each one got. Each line is scaled to its own high; the dashed line is Kay.
Names from the same era
Other common names that peaked within two years of Kay (1939).
Source: U.S. Social Security Administration national and state baby-name data, which covers names given to at least 5 babies of one sex in a year. About the data