How Many People Are Named Sydnei?
An estimated 623 people in the United States have the first name Sydnei. It is almost exclusively a female name. The average bearer is 23 years old, and Sydnei peaked in popularity in 2005 with 37 births that year.
Below you will find a full statistical profile of Sydnei 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 Sydnei paired with any surname.
Estimated Living Americans
623
About 1 in 550,167 people in the U.S.
Rarity
Very Rare
Predicted Gender
Female
100.0% confidence
Average Age
23
years old
Peak Year
2005
37 births
Total Registered
635
since 1880
Gender Distribution for Sydnei
Sydnei is almost exclusively a female name. Out of 635 total births registered, 100.0% were female.
Sydnei as a female name
Ranked #12,019 in 2020
8 female births in 2020
Peak: 2005 (37 births)
Sydnei: Popularity Over Time
SSA records for Sydnei span from the 1980s to the 2020s, covering 5 decades of naming data. The most popular decade for this name was the 2000s, when 274 babies were registered. Sydnei has declined significantly from its peak in the 2000s. Recent registrations are a fraction of what they were at the name's height.
Sydnei by Decade
How has Sydnei 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.
Sydnei by State
Birth registrations for Sydnei span all 5 states and territories in the SSA database. The highest counts are in Texas, Georgia, Louisiana. The lowest are in Tennessee, Missouri, Louisiana. On average, about 11 Sydneis were registered per state.
Sydnei + Last Name Combinations
How many people share a full name with Sydnei as the first name? Click a combination below to see the estimate, or search any pairing.
Names Similar to Sydnei
Other first names starting with S with a similar number of bearers.
Sydnei: Questions and Answers
How many people in the U.S. are named Sydnei?
We estimate approximately 623 people named Sydnei 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 550,167 Americans share this first name.
Is Sydnei a common name?
Sydnei is classified as "Very Rare" and is more popular than 86.6% of all first names in the SSA database. A total of 635 births have been registered with this name since 1880.
When was Sydnei most popular?
Sydnei reached peak popularity in 2005, when 37 babies were given this name. The average age of a living person named Sydnei is approximately 23 years old, reflecting when the name was most commonly given.
Is Sydnei a female name?
Sydnei is predominantly female. 100.0% of people with this name are female. See the gender breakdown above for full details.
How many Sydnei Smiths are there?
To find how many people share a specific full name, we combine first name and surname frequencies. Try: Sydnei Smith, Sydnei Johnson, Sydnei 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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