Theo

Theo is a male given name: 91% of people named Theo are men, and it is recorded as male in 8 of the 9 countries covered.

MaleHigh

Male 91%Female 9%

Theo · Théo

Verdict: Male
Male / female split: 91% male / 9% female
Confidence: High (64 or more weighted country observations)
Most common in: Netherlands, United States, Luxembourg
Also spelled: Théo
US births since 1880: 11,452 male / 3,211 female
Data: nam_dict (GFDL) + US SSA
Updated: 2026-09-11

How to address Theo

When you do not know their gender for certain, the full name with no title is the safe choice: "Dear Theo," in English, "Guten Tag Theo," in German. Theo is a male given name: about 91% of people named Theo are men. A quick look at a profile confirms it for certain.

Ready-made greetings in six languages

English

Dear Theo,

German

Guten Tag Theo,

French

Bonjour Theo,

Spanish

Estimado/a Theo:

Chinese

Theo您好：

Japanese

Theo様

English

Hi Theo,

German

Hi Theo,

French

Salut Theo,

Spanish

Hola Theo,

Chinese

Theo你好：

Japanese

Theoさん

Greeting generator

This is a statistical estimate, not a statement about the gender, identity or correct form of address of any particular person.

Country breakdown

Gender of the name Theo by country (nam_dict, 55 country columns)
Country	How common	Usually	Male share
Netherlands	common	man's name	98%
United States	common	man's name	78%
Luxembourg	common	man's name	98%
East Frisia	uncommon	man's name	98%
Belgium	uncommon	man's name	98%
Switzerland	uncommon	man's name	98%
Germany	uncommon	man's name	98%
France	uncommon	man's name	98%
Austria	rare	man's name	98%

United States birth data

11,452 male · 3,211 female · 14,663 births recorded

Male 78%Female 22%

Since 1980: 100% male.

Frequently asked questions

Is Theo a male or female name?

Theo is a male given name: 91% of people named Theo are men, and it is recorded as male in 8 of the 9 countries covered.

How do I address Theo in an email?

Is Theo a unisex name?

Theo is not a unisex name: 91% of people named Theo are men. Theo leans strongly male overall.

Sources

Gender by country: nam_dict, the c't first-names dictionary by Joerg Michael, roughly 44,000 names across 55 countries, licensed GFDL. US frequencies: United States Social Security Administration baby-name data, public domain. Method: how we classify names. Full dataset: data & licences. Data built 2026-09-11.

Cite this page

DearWho, "Is Theo a male or female name?", https://dearwho.vercel.app/name/theo (accessed 2026-09-11). Data: nam_dict (J. Michael, GFDL) and US SSA, built 2026-09-11.

BibTeX

@misc{dearwho_theo,
  title  = {Is Theo a male or female name?},
  author = {{DearWho}},
  year   = {2026},
  url    = {https://dearwho.vercel.app/name/theo},
  note   = {Data: nam_dict (GFDL), US SSA public domain}
}