How old is someone named Siobhan?
The average Siobhan is 37 years old.
Half of all living Siobhans are between 26 and 47.
When was Siobhan popular?
Siobhan is a steady name: popular for generations, with a peak in 1980 but no single era. You'll meet Siobhans of every age.
Popular names of 1980 · The most popular names of the 1980s →
Show the numbers by decade
| Born in | Babies born | Alive today |
|---|---|---|
| 1950s | 265 | 220 |
| 1960s | 869 | 770 |
| 1970s | 996 | 940 |
| 1980s | 2,086 | 2,000 |
| 1990s | 1,334 | 1,300 |
| 2000s | 758 | 750 |
| 2010s | 548 | 550 |
| 2020s | 543 | 540 |
How many Siobhans are still alive?
About 7,100 Siobhans are alive in the US today. That's 96% of the roughly 7,400 babies named Siobhan since 1956.
Nearly every Siobhan ever born is still alive, because almost all of them are young.
What generation is the name Siobhan?
About two in five living Siobhans are Millennials, born between 1981 and 1996.
- Boomer 8%
- Gen X 23%
- Millennial 38%
- Gen Z 18%
- Gen Alpha 13%
Is Siobhan an old name?
Somewhat. Siobhan is older than 62 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 Siobhan will be 47 in 2056, so the name is aging slowly.
Is Siobhan a boy or girl name?
Almost entirely girls: over 99.9% of living Siobhans are women.
Names the same age as Siobhan
NAME TWIN
Siobhan's name twin is Alison. Of all 3,713 names on AgeByName, Alison's age curve is the closest match to Siobhan's: 86% alike.
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Questions about the name Siobhan
How old is the average Siobhan?
The average Siobhan in the US is 37 years old. The median is 39, so half are older and half younger.
How many people are named Siobhan?
About 7,100 Siobhans are alive in the US today, out of roughly 7,400 babies given the name since 1956.
When was the name Siobhan most popular?
In 1980, when about 280 baby girls were named Siobhan.
Is Siobhan a Millennial name?
Partly. Millennials are the largest group, about 38% of living Siobhans, but the name spans several generations.
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