How Many People Are Named Ontarius?
An estimated 13 people in the United States have the first name Ontarius. It is almost exclusively a male name. The average bearer is 30 years old, and Ontarius peaked in popularity in 1991 with 7 births that year.
Below you will find a full statistical profile of Ontarius 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 Ontarius paired with any surname.
Key Insights
- Ontarius is exceptionally rare. Fewer than 100 people with this name are estimated to be alive in the U.S. today.
Estimated Living Americans
13
About 1 in 26,365,718 people in the U.S.
Rarity
Very Rare
Predicted Gender
Male
100.0% confidence
Average Age
30
years old
Peak Year
1991
7 births
Total Registered
13
since 1880
Gender Distribution for Ontarius
Ontarius is almost exclusively a male name. Out of 13 total births registered, 100.0% were male.
Ontarius as a male name
Ranked #9,994 in 2000
6 male births in 2000
Peak: 1991 (7 births)
Ontarius: Popularity Over Time
SSA records for Ontarius span from the 1990s to the 2000s, covering 2 decades of naming data. The most popular decade for this name was the 1990s, when 7 babies were registered. Ontarius remains highly popular today, with recent registration numbers near its historical peak.
Ontarius by Decade
How has Ontarius 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.
Ontarius + Last Name Combinations
How many people share a full name with Ontarius as the first name? Click a combination below to see the estimate, or search any pairing.
Names Similar to Ontarius
Other first names starting with O with a similar number of bearers.
Ontarius: Questions and Answers
How many people in the U.S. are named Ontarius?
We estimate approximately 13 people named Ontarius 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 26,365,718 Americans share this first name.
Is Ontarius a common name?
Ontarius is classified as "Very Rare" and is more popular than 33.2% of all first names in the SSA database. A total of 13 births have been registered with this name since 1880.
When was Ontarius most popular?
Ontarius reached peak popularity in 1991, when 7 babies were given this name. The average age of a living person named Ontarius is approximately 30 years old, reflecting when the name was most commonly given.
Is Ontarius a male name?
Ontarius is predominantly male. 100.0% of people with this name are male. See the gender breakdown above for full details.
How many Ontarius Smiths are there?
To find how many people share a specific full name, we combine first name and surname frequencies. Try: Ontarius Smith, Ontarius Johnson, Ontarius 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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