Name Legacy

Millie

Recorded 1880–2025 · United States

Millie was most popular in 2025, when 3,353 American babies were given the name — ranking #183 that year. In 2025 it ranked #183, with 3,353 births. Across 1880–2025 the Social Security Administration has recorded 46,138 people named Millie.

Most popular in2025
Rank that year#183
Births that year3,353
Total since 188046,138
Given to100% girls
Alive today~28,000
Median age7

Millie over time

18802025
Births per year. The dot marks Millie’s peak in 2025. Gaps are years the SSA suppressed, which it does for any name given to fewer than five babies.

How old is the name Millie?

The Social Security Administration’s records begin in 1880, and Millie is already there in that first year — so the name is older than the record and these figures cannot date it. It has been recorded in 146 of the 146 years since.

How many people are named Millie?

The Social Security Administration has recorded 46,138 American births named Millie between 1880 and 2025. That is recorded US births, not a world population — it counts people issued a Social Security number at birth in the United States. Of those, roughly 28,930 are estimated to be alive today.

How many babies were named Millie in 2025?

3,353 American babies were named Millie in 2025, ranking #183 that year.

Is Millie getting more or less popular?

Millie is rising. Across 2021–2025 it averaged 2,547 births a year, against 499 a year across 2011–2015 — a change of +410% over the decade.

Measured on recorded births. American births overall have fallen since 2007, so most established names lose births over any recent decade — a name can shed births and still hold its rank. Compare the rank above, which is measured against the other names of the same year.

Is Millie a boy’s or a girl’s name?

Across the whole record Millie is a girl’s name — 99.5% of the 46,138 Americans given it were girls and 0.5% were boys. In births since 2016 it is 100% girls and 0% boys.

Counted from every US birth the Social Security Administration recorded under this name, so it reflects use rather than opinion. A name given to fewer than five babies of one sex in a year is withheld at source and is not counted.

How old is someone named Millie?

Roughly 28,930 Americans named Millie are alive today — 63% of everyone ever recorded with the name. The median is 7 years old, and half are between 3 and 19.

An estimate, not a count. Recorded births are carried forward through the Social Security Administration’s 2023 period life table, by age and sex. That table describes mortality in one recent year, so it credits the oldest cohorts with today’s survival rather than the harsher rates they actually lived through — the further back a name peaked, the more this will overstate how many remain. It counts people issued a Social Security number at birth, not immigrants who arrived later.

Names that peaked alongside Millie

Where Millie is most concentrated

How much more common the name is in each state than across the country as a whole.

Explore further

See Millie on the interactive charts

About · Privacy · Contact
Source: U.S.A. Social Security Administration. Years 1880–2025. namelegacy.org