An estimated 15,310 living Americans are named Gillian.
How rare is Gillian?
Gillian is very rare among babies today, with 47 girls receiving the name in 2025, down 95.4% from its 1999 peak.
How old is the typical Gillian?
The median age of a living American named Gillian is approximately 27 years, with most bearers falling between 23 and 38 years old.
Is Gillian still popular?
No. Gillian is endangered as a baby name, down 95.4% from its 1999 peak with 47 births in 2025.
Where is Gillian most common?
Gillian has its strongest geographic signal in Connecticut, where it appears 3.4× more often than the national baseline.
1922Peak 19992025
Peak year
1999
Decline from peak
95.4%
2025
47
All-time
16,059
Diaspora map
Gillian spread fast — broke out in Connecticut, Massachusetts, New Hampshire, New Jersey, New York, Oregon, Rhode Island, Virginia, and Washington (1998) and ran high in 18 states within a decade.
Broke out: Connecticut, Massachusetts, New Hampshire, New Jersey, New York, Oregon, Rhode Island, Virginia, and Washington, 1998 · over-represented in 18 states over 4 years
