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, state-by-state birth registrations, and, when available, a 2020 Census snapshot showing who had the name at that point in time. 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 in the 2020 Census
The 2020 Census recorded 19,505 people with the first name Gillian, which placed it at #1,627 in the published first-name tables. This is a snapshot of people who already had the name in 2020. The estimated living count elsewhere on this page is different: it is a current estimate built from SSA birth records and age-based survival rates, so the two figures are not expected to match exactly.
Read this section as a snapshot of people who already had the name in 2020. The SSA charts elsewhere on this page are still the better way to see how the name rose, fell, or shifted across generations.
Gender in the 2020 Census
In the 2020 Census, Gillian was recorded as predominantly female. Out of 19,505 people with this name in that snapshot, 1.0% were male and 99.0% were female. That is very close to the long-run birth pattern in SSA records, where the name is female 99.6% of the time.
Census Count
19,505
people with this name
Census Rank
#1,627
among Census first names
Frequency Rate
6.46
per 100,000 people
Recorded Race and Hispanic Origin in the 2020 Census
In the 2020 Census, the first name Gillian was most commonly recorded among people who identified as White (78.88%). The next largest recorded groups were Black (7.12%) and Hispanic (6.21%).
These percentages describe the people who had the first name Gillian in the 2020 Census. They do not tell you the deeper meaning or origin of the name itself.
2020 Census demographic breakdown
Each row shows a recorded Census category for people with the first name Gillian.
| Group | Share | Count |
|---|---|---|
| White | 78.88% | 15,381 |
| Black | 7.12% | 1,389 |
| Hispanic | 6.21% | 1,211 |
| Two or More Races | 4.45% | 868 |
| Asian and Pacific Islander | 3.07% | 598 |
| American Indian and Alaska Native | 0.27% | 53 |
The Census published separate sex and race/origin tables for first names, so their total counts can differ slightly for the same name. That is why the race section focuses on the demographic mix rather than repeating a second headline count.
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.
How common was Gillian in the 2020 Census?
The 2020 Census recorded 19,505 people with the first name Gillian. That placed it at #1,627 in the published Census first-name tables, or 6.46 people per 100,000.
Why is the Census count different from the living estimate?
Because they measure different things. The Census number is a count of people with the name in 2020. The living estimate is a current model based on SSA birth records and survival rates, so it aims to estimate how many people with the name are alive now.
What does the SSA popularity chart show?
The popularity chart tracks birth registrations, not people currently alive. It shows how often Gillian was given to babies from 1880 through 2024, which is why it is the best tool on the page for seeing long-run naming trends.
What does the Census say about the gender split for Gillian?
In the 2020 Census snapshot, Gillian was recorded as predominantly female. The published split was 1.0% male and 99.0% female.
What does the Census say about the background of people named Gillian?
In the 2020 Census, the first name Gillian was most commonly recorded among people who identified as White (78.88%). The next largest recorded groups were Black (7.12%) and Hispanic (6.21%). These percentages describe the people who had the name in the 2020 Census, not the deeper meaning or origin of the name itself.
Why can the Census sex total and race total differ slightly?
The Census published separate first-name tables for sex and for race and Hispanic origin. Those totals can differ slightly for the same name, so the page uses them as two related snapshots rather than treating them as perfectly interchangeable counts.
Does every first name have Census demographic data?
No. The public Census first-name tables only include names that met the Bureau's publication rules. That means some names on this site will have SSA history but no published Census demographic snapshot.
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.
Why can Gillian have a lot of living bearers even if it is not trendy now?
Because a name can build up a large population over many decades. Gillian peaked in 1999, and the average living bearer is about 31 years old, so a name can still have millions of living bearers even after it stops feeling current for newborns.
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.
Search for a full name combination
How Many of Me