Brennan
Feminine · “Irish braon”
Brennan is given to both — 2,229 girls and 33,258 boys since 1880. See Brennan as a boy nameSee other names given to both
Ireland had its own legal system, the Brehon law, administered by a hereditary professional class and in use for more than a thousand years until the seventeenth century. The name Brennan is unrelated to it, which is worth saying because the two are constantly confused.
How old is the name Brennan?
Brennan first appears in US birth records in 1973 — 52 years ago. The typical Brennan alive today was born around 2004, making them about 21 years old. About 2,200 people named Brennan are estimated to be alive in the US today.
When was the name Brennan most popular?
Brennan peaked in 1994, reaching #1862 nationally. Today it ranks #9457, 7,595 places below that high. See the whole 1994 chart.
Lists built from the same records:
Where it comes from
From braon to Brennan
The story of Brennan
Brehon law, from breitheamh, a judge, was the native legal system of Ireland, recorded in law tracts from the seventh century onward and administered by hereditary families of jurists who trained for years in schools. It dealt in compensation rather than punishment, assessed by the status of the injured party, and it covered contract, marriage, bee-keeping, water rights and the liability of a dog's owner in remarkable detail. Women had property rights and grounds for divorce that English common law did not offer for another twelve hundred years. The system survived alongside English administration in the Gaelic areas until the early seventeenth century, when it was suppressed after the collapse of the Gaelic order. The tracts survive in large numbers and are among the most important sources for early medieval European law.
Meaningscholars disagree
Irish braon, a drop or sorrow
Brennan is the anglicization of several distinct Irish surnames, chiefly O Braonain, descendant of Braonan, built on braon, a drop of water or sorrow, with a diminutive ending. It is unrelated to breitheamh, a judge, the word behind Brehon law, despite the resemblance. The American female peak is 1994.
How the name formed
- braon
- O Braonain
- Brennan
Related forms: O Braonain · Brennen
Pronouncing Brennan
BREN-un
Two syllables, stress on the first. It is said the same in Irish and English, which is unusual for an anglicized Irish surname.
Nicknames for Brennan
Moderate
What the data says
146 years of official birth records
The long climb, and where it stands now
The same years in position rather than babies
- First recorded
- 1973
- Most girls named
- 2007100 — the highest on record
- Peak rank
- #1862reached in 1994
- Change vs 2024
- −47.4%10 in 2025, from 19
Rank is a position, a count is a headcount, and they move independently — a name can hold its rank while the number of babies behind it falls. Source: U.S. Social Security Administration.
Brennan in other languages
The same name elsewhere
- O Braonain in Irish — related form
- Brennen in English — spelling variant
Strongest US states over the last decade: Texas, North Carolina.
Brennans among us
people named Brennan are estimated to be alive in the US today
About 1 girl in 160,727 born in 2025 was named Brennan
Estimated from SSA birth records and published actuarial life tables. Method
Is it right for you
What happens to a name after it peaks
The Mabry test
Every popular name lives one long story — a climb, a peak, a slow settling back. Brennan's later chapters haven't been written yet, so we borrowed them: Mabry climbed just as high around 1908, and its whole arc is on record. Line the two peaks up, and Mabry's path sketches the road Brennan is walking now.
Brennan sits in the calm middle of the cycle — neither chasing a wave nor sliding off one. Middle-of-the-cycle names age slowly and predictably.
A scored estimate from 146 years of naming cycles — not a prophecy. Great names outlive statistics. How this is scored
Brennan beside its neighbors
The names ranked closest to Brennan in 2025, in babies rather than position — the bars are to scale.
US girls given each name in 2025.
The trade-off
- Bren works as a short form.
- It is a genuine Irish surname with a documented history.
- The spelling and pronunciation agree.
- It is read as a boy's name by most Americans.
- Several distinct Irish surnames produced the same spelling.
- It is unrelated to Brehon law despite the resemblance.
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What they receive
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Brennan
Feminine · #9457 in the U.S.
Frequently asked
- How many Brennans are there in the world?
- No country counts the world's names, so there is no worldwide figure — anyone quoting one is estimating. About 2,200 people named Brennan are estimated to be alive in the US today.
- How popular is the name Brennan in 2025?
- Brennan ranks #9457 among US girl names in 2025, with 10 babies given the name.
- How rare is the name Brennan?
- About 1 in every 160,727 US girls born in 2025 was named Brennan — 10 in all.
- Will my child share the name Brennan with classmates?
- Brennan will almost certainly be the only one in school.
Ranked beside Brennan
Names sitting at a similar level of popularity right now.
Leta#9457 · Inga#9457 · Delphia#9457 · Cammie#9457 · Lisandra#9457 · Amee#9457 · Venecia#9457 · Annetta#9457
Looking for what else is popular rather than what resembles Brennan? See the current top 100.
Choosing between Brennan and another name?
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US figures from the Social Security Administration. 1880–2025. Data & methodology
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