How Many People Are Named Gillian?
An estimated 15,315 people in the United States have the first name Gillian. It is almost exclusively a female name. The average bearer is 31 years old, and Gillian peaked in popularity in 1999 with 1,030 births that year.
Below you will find a full statistical profile of Gillian as a first name in the United States, including gender data, a year-by-year popularity timeline going back to 1880, a decade breakdown, and state-by-state birth registrations. You can also check how many people share the full name Gillian paired with any surname.
Key Insights
- While Gillian is overwhelmingly female, 68 male births have been registered with this name since 1880.
Estimated Living Americans
15,315
About 1 in 22,380 people in the U.S.
Rarity
Uncommon
Predicted Gender
Female
99.6% confidence
Average Age
31
years old
Peak Year
1999
1,030 births
Total Registered
16,079
since 1880
Gender Distribution for Gillian
Gillian is almost exclusively a female name. Out of 16,079 total births registered, 99.6% were female.
Gillian as a male name
Ranked #11,190 in 2016
6 male births in 2016
Peak: 1988 (10 births)
Gillian as a female name
Ranked #3,124 in 2024
51 female births in 2024
Peak: 1999 (1,022 births)
Gillian: Popularity Over Time
SSA records for Gillian span from the 1920s to the 2020s, covering 11 decades of naming data. The most popular decade for this name was the 2000s, when 5,503 babies were registered. Gillian has declined significantly from its peak in the 2000s. Recent registrations are a fraction of what they were at the name's height.
Gillian by Decade
How has Gillian tracked across different eras? The table below groups all SSA birth registrations into 10-year periods, with separate male and female counts. The colored bar shows each decade's share relative to the peak.
Gillian by State
Birth registrations for Gillian span all 47 states and territories in the SSA database. The highest counts are in California, New York, Texas. The lowest are in Vermont, Hawaii, Mississippi. On average, about 271 Gillians were registered per state.
Gillian + Last Name Combinations
How many people share a full name with Gillian as the first name? Click a combination below to see the estimate, or search any pairing.
Names Similar to Gillian
Other first names starting with G with a similar number of bearers.
Gillian: Questions and Answers
How many people in the U.S. are named Gillian?
We estimate approximately 15,315 people named Gillian are alive in the United States today. This is based on SSA birth records from 1880 to 2024, adjusted for mortality using CDC life tables. About 1 in 22,380 Americans share this first name.
Is Gillian a common name?
Gillian is classified as "Uncommon" and is more popular than 98.2% of all first names in the SSA database. A total of 16,079 births have been registered with this name since 1880.
When was Gillian most popular?
Gillian reached peak popularity in 1999, when 1,030 babies were given this name. The average age of a living person named Gillian is approximately 31 years old, reflecting when the name was most commonly given.
Is Gillian a female name?
Gillian is predominantly female. 99.6% of people with this name are female. See the gender breakdown above for full details.
How many Gillian Smiths are there?
To find how many people share a specific full name, we combine first name and surname frequencies. Try: Gillian Smith, Gillian Johnson, Gillian Williams. You can also search any combination on our homepage.
Where does this data come from?
Our estimates use Social Security Administration birth records (1880 to 2024), adjusted for survival using CDC 2023 life tables broken down by sex. The U.S. population figure (342,754,338) is from the Census Bureau's July 2025 estimate. Full methodology.
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