Girls' name · peaked in 1999
Gillian name popularity since 1925
16,122 babies born in the US from 1925 to 2025 were named Gillian. Half of them were born in 1999 or earlier, so the typical Gillian is about 27 years old in 2026. Gillian peaked in 1999 as the #303 name for girls, and it was outside the top 1,000 in 2025.
Key facts
- US babies since 1925
- 16,122
- Named Gillian, 1925–2025
- In 2025
- Not top 1,000
- #3,307 for girls in 2025
- Girls / boys
- 99.6% girls
- 16,054 girls · 68 boys
- Most popular in
- Connecticut
- 2.35× its national share
Peak year is the year Gillian 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.
Gillian births per year, 1925–2025
1999 was the biggest year for Gillian both by count and as a share of all babies.
- Fastest rise: Between 1994 and 1999, Gillian became 6.4× more common, from 1 in 11,000 baby girls to 1 in 1,740.
- Steepest fall: Between 2008 and 2013, its share of baby girls fell by 62%, from 1 in 5,580 to 1 in 14,600.
Shaded on the chart. Both compare Gillian's share of all US girls five years apart, counting only years with at least 100 babies named Gillian.
Decade by decade
Babies named Gillian 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 | 0 | 0 | – |
| 1930s | 12 | 0 | Under 5 |
| 1940s | 128 | 0 | #2,515 |
| 1950s | 234 | 0 | #1,994 |
| 1960s | 758 | 0 | #1,190 |
| 1970s | 1,329 | 8 | #1,155 |
| 1980s | 2,384 | 15 | #738 |
| 1990s | 4,152 | 20 | #871 |
| 2000s | 5,489 | 14 | #661 |
| 2010s | 1,263 | 11 | #1,746 |
| 2020–25 | 305 | 0 | #3,307 |
Ranks count every name given to at least 5 girls that year, so they can go past 1,000. "Under 5" means fewer than 5 girls got the name.
Generation fingerprint
53.7% of babies named Gillian from 1925 to 2025 were born in the Gen Z years (1997–2012). The full split by generation:
Where Gillian is most popular
The index compares Gillian'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 Gillian.
| State | Index | Babies |
|---|---|---|
| Connecticut | 2.35× | 329 |
| Massachusetts | 2.06× | 633 |
| New Jersey | 2.06× | 733 |
| New York | 1.82× | 1,781 |
| Washington | 1.82× | 392 |
Names with a similar story
Of the other 1999 names on this site, these six had the share of babies closest in shape to Gillian's from 1925 to 2025, however common each one got. Each line is scaled to its own high; the dashed line is Gillian.
Names from the same era
Other common names that peaked within two years of Gillian (1999).
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