Theo
Feminine · “god”
Theo is given to both — 3,503 girls and 35,830 boys since 1880. See Theo as a boy nameSee other names given to both
Theo was a girls' name before it was a boys' one in American records. In the 1880s it sat inside the top six hundred for girls, standing as the everyday form of Theodora, Theodosia and Theophila — the whole family of Greek god-names that Victorian America liked. Its later career as a short form of Theodore for boys is the second act, not the first.
How old is the name Theo?
Theo was already in use when US birth records began in 1880 — it is at least 145 years old. The typical Theo alive today was born around 1923, making them about 102 years old. About 900 people named Theo are estimated to be alive in the US today.
When was the name Theo most popular?
Theo peaked in 1887, reaching #512 nationally. Today it ranks #5722, 5,210 places below that high. See the whole 1887 chart.
Where it comes from
From theos to Theo
The story of Theo
The theos names were among the most durable in the Greek-speaking Christian world, and the Empress Theodora, wife of Justinian, gave the feminine form imperial weight. English-speaking families took Theodora and Theodosia up in the eighteenth and nineteenth centuries, and American usage was strong enough by the 1880s that the short form Theo appears on birth records for girls in real numbers. That use faded after 1900 as the long names went out of fashion. Theodore's own revival after 2010 brought Theo back into wide circulation as a boy's name, and only recently has it begun to return on girls, now usually as a standalone rather than as a clipping.
Meaning
god — from Theodora, 'gift of God'
Greek theos means god, and it is the first element of a large family of names: Theodora and Theodore, 'gift of god', from theos and doron; Theodosia, 'giving to god'; Theophila, 'friend of god'; Dorothea, which is the same two elements in the other order. Theo is the shared front of all of them, and on a nineteenth-century American girl it almost always stood for Theodora or Theodosia rather than for anything on its own.
How the name formed
- theos
- Theodora
- Theo
Related forms: Theodora · Theodore · Feodora · Theo
Pronouncing Theo
THEE-oh
Two syllables, stress on the first, with the unvoiced th of think. Some European languages say TAY-oh, and Dutch and German bearers in America may keep that. The English saying is the default.
Nicknames for Theo
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
- 1880
- Most girls named
- 1919109 — the highest on record
- Peak rank
- #512reached in 1887
- Change vs 2023
- −50.0%21 in 2025, from 42
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.
Theo in other languages
The same name elsewhere
- Theodora in Greek — related form
- Theodore in French — related form
- Feodora in Russian — related form
- Theo in Dutch — same name
Strongest US states over the last decade: California, Kansas, Pennsylvania.
Theos among us
people named Theo are estimated to be alive in the US today
About 1 girl in 76,537 born in 2025 was named Theo
Estimated from SSA birth records and published actuarial life tables. Method
Is it right for you
What happens to a name after it peaks
Fashion outlook
Theo 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
Theo beside its neighbors
The names ranked closest to Theo in 2025, in babies rather than position — the bars are to scale.
US girls given each name in 2025.
The trade-off
- It is short, easy to spell and pronounceable in most European languages.
- It has a documented history on American girls that predates its modern boys' use.
- Theodora, Theodosia and Thea are all available as longer or alternate forms.
- In current American use it is overwhelmingly male, and will be read that way by default.
- It is a short form by origin, which leaves no formal version unless one is chosen.
- Theo and Thea are one letter apart and will be swapped in writing.
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What they receive
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Theo
Feminine · #5722 in the U.S.
Frequently asked
- How many Theos are there in the world?
- No country counts the world's names, so there is no worldwide figure — anyone quoting one is estimating. About 900 people named Theo are estimated to be alive in the US today.
- How popular is the name Theo in 2025?
- Theo ranks #5722 among US girl names in 2025, with 21 babies given the name.
- How rare is the name Theo?
- About 1 in every 76,537 US girls born in 2025 was named Theo — 21 in all.
- Will my child share the name Theo with classmates?
- Theo will almost certainly be the only one in school.
Ranked beside Theo
Names sitting at a similar level of popularity right now.
Rosina#5722 · Delores#5722 · Vaughn#5722 · Roseline#5722 · Loyal#5722 · Missy#5722 · Danitza#5722 · Margret#5722
Looking for what else is popular rather than what resembles Theo? See the current top 100.
Choosing between Theo and another name?
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US figures from the Social Security Administration. 1880–2025. Data & methodology
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