How Many People Are Named Oneil?
An estimated 1,076 people in the United States have the first name Oneil. It is predominantly male (99.0%). The average bearer is 42 years old, and Oneil peaked in popularity in 1924 with 43 births that year.
Below you will find a full statistical profile of Oneil 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 Oneil paired with any surname.
Estimated Living Americans
1,076
About 1 in 318,545 people in the U.S.
Rarity
Rare
Predicted Gender
Male
99.0% confidence
Average Age
42
years old
Peak Year
1924
43 births
Total Registered
1,766
since 1880
Gender Distribution for Oneil
Oneil is almost exclusively a male name. Out of 1,766 total births registered, 99.0% were male.
Oneil as a male name
Ranked #9,604 in 2024
8 male births in 2024
Peak: 1924 (38 births)
Oneil as a female name
Ranked #5,683 in 1924
5 female births in 1924
Peak: 1918 (7 births)
Oneil: Popularity Over Time
SSA records for Oneil span from the 1890s to the 2020s, covering 13 decades of naming data. The most popular decade for this name was the 1920s, when 269 babies were registered. Oneil has declined significantly from its peak in the 1920s. Recent registrations are a fraction of what they were at the name's height.
Oneil by Decade
How has Oneil 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.
Oneil by State
Birth registrations for Oneil span all 6 states and territories in the SSA database. The highest counts are in New York, Louisiana, South Carolina. The lowest are in North Carolina, Maine, Florida. On average, about 60 Oneils were registered per state.
Oneil + Last Name Combinations
How many people share a full name with Oneil as the first name? Click a combination below to see the estimate, or search any pairing.
Names Similar to Oneil
Other first names starting with O with a similar number of bearers.
Oneil: Questions and Answers
How many people in the U.S. are named Oneil?
We estimate approximately 1,076 people named Oneil 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 318,545 Americans share this first name.
Is Oneil a common name?
Oneil is classified as "Rare" and is more popular than 90.6% of all first names in the SSA database. A total of 1,766 births have been registered with this name since 1880.
When was Oneil most popular?
Oneil reached peak popularity in 1924, when 43 babies were given this name. The average age of a living person named Oneil is approximately 42 years old, reflecting when the name was most commonly given.
Is Oneil a male name?
Oneil is predominantly male. 99.0% of people with this name are male. See the gender breakdown above for full details.
How many Oneil Smiths are there?
To find how many people share a specific full name, we combine first name and surname frequencies. Try: Oneil Smith, Oneil Johnson, Oneil 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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