How old is someone named Sidney?
The average Sidney is 43 years old.
Half of all living Sidneys are between 24 and 66. The average sits between a large young group and an older one, so many Sidneys are much younger than 43.
When was Sidney popular?
Parents have been choosing Sidney less often since its peak in 1918; 251 babies got the name in 2025.
Popular names of 1918 · The most popular names of the 1910s →
Show the numbers by decade
| Born in | Babies born | Alive today |
|---|---|---|
| 1900s | 2,178 | 0 |
| 1910s | 13,231 | 0 |
| 1920s | 14,769 | under 100 |
| 1930s | 10,117 | 1,300 |
| 1940s | 10,559 | 4,600 |
| 1950s | 10,524 | 7,000 |
| 1960s | 7,415 | 6,000 |
| 1970s | 4,144 | 3,700 |
| 1980s | 4,114 | 3,900 |
| 1990s | 10,793 | 11,000 |
| 2000s | 11,130 | 11,000 |
| 2010s | 4,885 | 4,800 |
| 2020s | 1,727 | 1,700 |
How many Sidneys are still alive?
About 55,000 Sidneys are alive in the US today. That's 50% of the roughly 110,000 babies named Sidney since 1880.
Roughly half of all Sidneys ever born are still living.
What generation is the name Sidney?
About one in three living Sidneys are in Gen Z, born between 1997 and 2012.
Is Sidney an old name?
Somewhat. Sidney is older than 70 in 100 names on AgeByName, but younger than plenty of classics.
Looking ahead: if babies keep getting the name at today's pace, the typical Sidney will be 50 in 2056, so the name is aging slowly.
Is Sidney a boy or girl name?
Both. 40% of living Sidneys are women and 60% are men.
The women average 28 and the men 53. It was mostly a boys' name before 1970; since 1995, 70% of babies named Sidney have been girls.
Names the same age as Sidney
NAME TWIN
Sidney's name twin is Irvin. Of all 3,713 names on AgeByName, Irvin's age curve is the closest match to Sidney's: 90% alike.
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Questions about the name Sidney
How old is the average Sidney?
The average Sidney in the US is 43 years old. The median is 35, so half are older and half younger.
How many people are named Sidney?
About 55,000 Sidneys are alive in the US today, out of roughly 110,000 babies given the name since 1880.
When was the name Sidney most popular?
In 1918, when about 1,900 baby boys were named Sidney.
Is Sidney a Gen Z name?
Partly. Gen Z are the largest group, about 32% of living Sidneys, but the name spans several generations.
Is Sidney a boy or girl name?
Both. 40% of living Sidneys are women and 60% are men. The women average 28 and the men 53. It was mostly a boys' name before 1970; since 1995, 70% of babies named Sidney have been girls.
Estimates from Social Security Administration baby-name records (births 1880–2025) and SSA cohort life tables (2026 Trustees Report). Updated each spring. How we calculate this