Head to head · Boys' names
Aaron vs Theo
#80 vs #82 in 2025
Aaron is a whisker ahead (#80 vs #82 in 2025), but the curves point different ways: Aaron is stepping back from its peak, Theo is climbing the charts fast. On momentum, Theo has the edge.
Cast your vote
Which one would you pick?
Your gut first, the numbers after — the split shows once you pick.
The tale of the tape
On the charts, Aaron leads 4 measures of 6; Theo leads 1.
Ranks, counts and years are measured in the official US birth record; the classroom and living figures are estimates computed from it. The dot marks the side each measure favours on the charts — more common, not better.
What the records say
146 years of US births, drawn on one scale
Two curves, one scale
Who owned which decade
- 1880s: Aaron #148, Theo #648 — Aaron higher
- 1890s: Aaron #179, Theo #612 — Aaron higher
- 1900s: Aaron #181, Theo #488 — Aaron higher
- 1910s: Aaron #188, Theo #578 — Aaron higher
- 1920s: Aaron #218, Theo #641 — Aaron higher
- 1930s: Aaron #246, Theo #755 — Aaron higher
- 1940s: Aaron #247, Theo #1024 — Aaron higher
- 1950s: Aaron #213, Theo #1241 — Aaron higher
- 1960s: Aaron #130, Theo #1396 — Aaron higher
- 1970s: Aaron #36, Theo #1479 — Aaron higher
- 1980s: Aaron #31, Theo #1488 — Aaron higher
- 1990s: Aaron #33, Theo #1584 — Aaron higher
- 2000s: Aaron #50, Theo #1188 — Aaron higher
- 2010s: Aaron #53, Theo #523 — Aaron higher
- 2020s: Aaron #71, Theo #109 — Aaron higher
Aaron stood higher in every recorded decade — 15 of 15.
Rank by decade
| Decade | Aaron | Theo |
|---|---|---|
| 1880s | #148 | #648 |
| 1890s | #179 | #612 |
| 1900s | #181 | #488 |
| 1910s | #188 | #578 |
| 1920s | #218 | #641 |
| 1930s | #246 | #755 |
| 1940s | #247 | #1024 |
| 1950s | #213 | #1241 |
| 1960s | #130 | #1396 |
| 1970s | #36 | #1479 |
| 1980s | #31 | #1488 |
| 1990s | #33 | #1584 |
| 2000s | #50 | #1188 |
| 2010s | #53 | #523 |
| 2020s | #71 | #109 |
Average national rank across each decade. A dash means the name sat outside the recorded top of that decade.
Around the world
Aaron
- France#20
- Scotland#95
Theo
- Scotland#6
- England & Wales#12
- Canada#17
National statistics offices, latest published year.
The names themselves
Meaning, roots, sound and the people who carried each
Where each name comes from
Aaron
Not established
The Hebrew Aharon has never been given a secure etymology. Traditional Jewish readings link it to har, 'mountain', hence glosses like 'mountain of strength' or 'exalted'; many scholars instead read it as Egyptian in origin, alongside other names in the same priestly family such as Moses and Phinehas. What is documented is the bearer rather than the sense: Aaron the Levite, spokesman for Moses and first of the priestly line.
Aharon → Aarōn → Aaron
How it traveled
The name is Hebrew, and its earliest appearance is in the Torah, where Aaron is Moses' elder brother and the founder of the priesthood. The Greek translators of the Hebrew Bible rendered it Aarōn, and the Latin Vulgate kept that form, which is why English-speaking countries spell it with two a's rather than the Hebrew-style Aharon.
Theo
'Gift of God' when it comes from Theodore; 'people' when it comes from Theobald or Theodoric
Theo sits at the meeting point of two unrelated words. Through Greek Theodoros it joins theos, 'god', with doron, 'gift' — the classic reading, 'gift of God'. But Dutch and German Theo just as often shortens Theobald or Theodoric, where the first element is Germanic theud, 'people' or 'tribe'. Both roads are real, and which one applies depends on the longer name behind it — or on nothing at all, if Theo is the whole name on the birth certificate.
Theodoros → Theodorus → Theodore → Theo
How it traveled
Theodoros was a common Greek name across the eastern Mediterranean and the Byzantine world, borne by early Christian saints and passed into Latin as Theodorus, then into English as Theodore. Separately, Germanic-speaking Europe had its own crop of theud- names — Theobald, Theodoric — which shortened to the same two syllables.
Where a reading is contested the note says so — this page does not turn a guess into a fact. The chain is each name's recorded forms, oldest first; the story is its opening, told in full on the name's own page.
Out loud, and in short
Aaron
AIR-un
The usual American pronunciation is AIR-un, which makes it a near or exact homophone of Erin in most US accents. Many British, Irish and Israeli speakers say AR-un or a-ha-RON instead. Both English versions are correct; expect to state which one you use.
- Ron — Informal clip from the second syllable; also a long-established given name in its own right, usually from Ronald.
- Ronnie — Informal and affectionate; stands alone as a given name for men and women both.
- Ari — Standard short form of Aharon in Hebrew-speaking families, and widely used as an independent given name.
- Air — Playground-level clip, heard mainly in American accents that say the first syllable as AIR.
Theo
THEE-oh
In English the th is the soft, breathy kind, as in 'thin'. Dutch, German and French speakers say it closer to TAY-oh, and Spanish and Italian speakers tend to reach for Teo — worth knowing if the family spans more than one language.
- Teddy — Used mainly when the full name on paper is Theodore; less natural if Theo is the legal name.
- Ted — The older English short form of Theodore, still in use among adults; also stands alone as a given name.
- Teo — Informal respelling, and the standard form in Italian and Spanish.
Who has carried each name
Aaron
Aaron Judge (b. 1992) — Yankees slugger who set the American League home-run record
Aaron Burr (b. 1756) — The vice president who shot Hamilton in the famous duel
Theo
Theo James (b. 1984) — The White Lotus and Divergent star
Source: Wikidata — the one source on this page that is not an official agency.
Is it right for you
The differences that decide it, laid out by what you want
Choose by what you want
Choose Aaron if you want…
- a name past its most crowded yearsAaron is stepping back from its peak
- a name that ages quietlyan estimated 12% chance of feeling dated by 2040, against 58% for Theo
Choose Theo if you want…
- a name on the way upup 90 places on the charts in five years
- a name that charts abroad tooTheo is on the national lists of Scotland, England & Wales and Canada
- a name that feels very nowTheo is climbing the charts fast
Each line is a measured difference between the two names — a rank, a count, a recorded form — never a judgement of either. Save the one that answers your question; it lands on your shortlist.
The trade-offs, name by name
Aaron
Strengths
- An unbroken written record from the Hebrew Bible to the present, which means no explaining where it comes from.
- Recognized across languages and scripts — Aharon in Hebrew, Harun in Arabic, Aarón in Spanish, and charting today in places as different as France and Scotland.
- The spelling is the standard English one, familiar in print for centuries, so it needs no defense even if it needs the occasional repeat.
To consider
- The double a at the start is genuinely tricky in writing. Expect Aron, Arron and Erin over a lifetime, and a habit of spelling it out.
- In most American accents it sounds identical to Erin, which occasionally causes confusion on rosters and over the phone.
- The AIR-un and AR-un pronunciations both have long histories, so relatives in different countries may say it differently.
Theo
Strengths
- Short, phonetic and read correctly at first sight by most English speakers; almost nothing to spell out over the phone.
- Charts in Scotland, England and Wales, and Canada as well as the US — it crosses borders without changing shape.
- Works either as a complete name or as the everyday form of Theodore, Theodoric or Theobald, so the formal register is there if wanted.
To consider
- It is climbing quickly, and the pattern of that climb means classmates named Theo are likelier over the next decade than they have been so far.
- It sits close to Leo and to Theodore in sound; expect occasional mix-ups, and expect people to assume the birth certificate says Theodore.
- If you want Theodore on paper, decide early which name the family will actually use — households often drift, and the child ends up answering to both.
Documented properties of each name — how it spells, travels and shortens — not opinions about the child.
How each is likely to age
Aaron
12%chance Aaron feels dated by 2040
Aaron has held the top-100 across 6 different decades — it has never depended on fashion, and names like that read the same at any age.
Theo
58%chance Theo feels dated by 2040
Theo is climbing fast right now. Steep climbs tend to come with steep descents — the quicker a name arrives, the more firmly it belongs to its moment.
A reading of where each name sits on the long naming cycle — computed, not measured, and explained on the data page.
With your last name
Say both in full. The notes are facts about letters and sound — a rhyme, a shared initial, the monogram — not a verdict on either name.
Type a last name to hear Aaron and Theo in full.
Weighing the whole shortlist? Run the full comparison — up to eight names with your last name, initials, classroom projections and a printable report.
Decide together
Nobody names a baby alone
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More head-to-heads
Same measures, different pair. Sixty more are dealt daily in the arena.
Lists that carry both names
Every list here names both Aaron and Theo — the same style, ranked by the same records.
Aaron or Theo — the short answers
- Which is more popular, Aaron or Theo?
- Aaron, in 2025: Aaron ranked #80 with 4,041 babies; Theo ranked #82 with 3,945 babies.
- Which name is rising faster, Aaron or Theo?
- Theo. Over the last five years Aaron moved down 17 places; Theo moved up 90 places.
- Which is the older name, Aaron or Theo?
- The US record cannot say: both were already in use when it began in 1880.
- How many people are named Aaron and Theo?
- About 564,000 people named Aaron are estimated to be alive in the US today. About 32,500 people named Theo are estimated to be alive in the US today.
- Will there be other Aarons or Theos in the classroom?
- Aaron will almost certainly be the only one in school. Theo will almost certainly be the only one in school.
US figures from the Social Security Administration, 1880–2025; international figures from national statistics agencies. Votes are battle voters on this site, not the birth record. Data & methodology
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