Unisex name · since 1880

Theo

Theo has 35,830 recorded births since 1880 in federal Social Security data, most heavily in 2023 -- full year-by-year trend, decade aggregates, and state rankings follow.

#609 of 45,481
all-time among boys
#82 of 13,930
2025 SSA year
35,830
born since 1880
2020s
peak decade

Yes -- Theo is the #82 most popular unisex name in the U.S. today, with 35,830 recorded since 1880.

Theo has 35,830 recorded births among boys since 1880, per the U.S. Social Security Administration, ranked #82 as of the latest data, more common than 99.4% of boys, busiest in the 2020s -- see the year-by-year trends, decade totals, and state-level distribution below, all drawn directly from SSA birth-registration files spanning 1880 to 2025.

  • #609 of 45,481 all-time among boys
  • #82 of 13,930 2025 SSA year
  • 35,830 born since 1880
  • 2020s peak decade

Data updated Aug 2026

The verdict

According to the U.S. Social Security Administration, Theo ranks #609 of 45,481 boys' names by all-time recorded births (highest first) and #82 of 13,930 among boys' names in 2025. 35,830 born since 1880, peaking in the 2020s.

#609 of 45,481
all-time among boys
#82 of 13,930
2025 SSA year
35,830
born since 1880
2020s
peak decade
0%100%Median name50%99.4%
Theo vs. every other boys name in current SSA rankings
Upper archive tier
All-time archive position

Theo's 35,830 recorded births place it above 98.66% of the 45,481 boys names in the full SSA archive.

51 jurisdictions
State-record footprint

51 jurisdictions carry state-level records, led by California.

How Theo compares

35,830 Top 5% higher than 95% of 13,930 names currently given to boys

Based on all-time total births among currently-ranked boys names. Names with fewer occurrences are grouped into wider buckets on the right.

Source U.S. Social Security Administration, national baby name data

How the numbers stack up

Theo's all-time total is 97x the median boys name, and Liam still leads by a wide margin.

Metric Theo Median boys name (Takari) #1 boys name (Liam)
All-time total births 35,830 369 358,536
Peak-year births 4,140 34 22,252

Theo's usage pattern, beyond the headline number

Divide Theo's SSA record in two at 1953 and the more recent half accounts for 91% of all births, the earlier half the remaining 9%, consistent with a name still gaining ground rather than fading. Its calmest year was 1884, with only 7 births recorded -- set against the 2023 peak of 4,140, that's the full swing in one name's fortunes.

Theo popularity over time - boys

Annual U.S. births registered with the Social Security Administration · 1880–2025

Top 100 boys' name
Peak year (2023)
4,140
Annual births at peak, across 146 years of records
01,0002,0003,0004,0005,000 188018991918193719561975199420132025 3,945

Theo popularity over time - girls

3,503 total births recorded since 1880 (Theo as girls' name)

Unisex variant - 3,503 births
050100150 188018931906191919321945195820022025 21

Theo by decade

2020s is the heaviest window (20,784 births, 58% of the file).

2020s was Theo's strongest decade.

20,784 babies received the name during that ten-year window, about 58% of all-time use.

Theo births by decade

Total births in each ten-year window

births

What this shows Peak: 2020s at 20,784 births (58% of all-time use).

Source U.S. Social Security Administration · Baby Names As of August 2026

How Theo compares to similarly-sized names

Years in SSA records vs. share of all-time use concentrated in the single peak year, among 15 boys names closest to Theo's total volume

Theo vs 15 similarly-sized boys names Scatter plot of 16 data points. 0%5%10%15%20% 050100150200 New & already peakedOld name, single-era peakNew & still diversifyingLong history, steady all along Years in SSA records % of total births in the single peak year -93, 4.9%-104, 2.7%-145, 3%-140, 3.5%-114, 2.9%-135, 2.9%-146, 2%-114, 6%-120, 2.7%-107, 5.2%-146, 1.3%-40, 16.6%-141, 2.7%-126, 6.6%-145, 5.2%Theo-146, 11.6%Theo
Theo vs 15 similarly-sized boys names

Theo by state

Where Theo concentrates geographically, total births since 1880

Geographically diffuse
Top 8 states by recorded births for the name Theo
Rank State Visual share Births Share of total
#1 California
3,939 11.0%
#2 Texas
2,273 6.3%
#3 New York
2,258 6.3%
#4 Florida
1,709 4.8%
#5 Illinois
1,323 3.7%
#6 Massachusetts
1,287 3.6%
#7 Pennsylvania
1,222 3.4%
#8 Ohio
1,099 3.1%
California share of Theo's total US births 11.0%
Even split

3,939 of 35,830 births nationwide. Compared to a flat distribution across 51 reporting states.

Theo appears in 51 states. Explore state details →

Frequently Asked Questions

How popular is the name Theo? ▼
Theo has been given to 35,830 babies in the U.S. since 1880, according to SSA data. Its archive ordinal is #609 of 45,481 among boys' names (total births, highest first). Among boys in 2025, it is #82 of 13,930. 4,140 babies were born in 2023, its single highest year.
Where does Theo sit in the SSA name archive? ▼
According to the U.S. Social Security Administration, Theo ranks #609 of 45,481 boys' names by all-time recorded births (highest first) and #82 of 13,930 among boys' names in 2025. All-time ordinal matches browse popularity (total births DESC); the current ordinal uses the 2025 SSA file. See /methodology#corpus-placement.
When was Theo most popular? ▼
Theo was most popular in the 2020s decade with 20,784 total births. The single peak year was 2023.
Where is Theo most popular? ▼
The top states for the name Theo are California (3,939 births), Texas (2,273 births), New York (2,258 births).
Is Theo a unisex name? ▼
Yes, Theo is used for both boys and girls. As a boy's name it has 35,830 births, and as a girl's name it has 3,503 births.
How long has the name Theo been used? ▼
Theo has been recorded in Social Security data since 1880, spanning 146 years of data through 2025.
What names are similar to Theo? ▼
Names with a similar sound or spelling include Theodore, Theron, Theadore, Theophilus, and 4 more. These share a common prefix and are also used for boys.

What to do with Theo's data

  • California records the most Theos (3,939 births) -- see the full state breakdown if geography matters to your decision. California names

Figures reflect SSA-reported births only; see the methodology above for the privacy-suppression floor.

Keep exploring Theo

Nearby Names Like Theo

Names with a similar sound, spelling, or feel to Theo

Theodore Boy
#4 317,206 births
Theron Boy
#2453 12,960 births
Theadore Boy
#12032 4,005 births
Theophilus Boy
#2392 2,448 births
Theodis Boy
2,244 births

Compare Theo side by side: Theo vs Theodore Theo vs Theron Theo vs Theadore

Or pick any two names to compare →

Related Names

Names with a similar popularity rank to Theo

August #81
68,182 births · Peak 2025
Ian #83
257,664 births · Peak 2005
Aaron #80
614,462 births · Peak 1989
Adriel #84
33,645 births · Peak 2025
Axel #79
72,459 births · Peak 2020
Luka #85
28,959 births · Peak 2025
Walker #78
47,914 births · Peak 2022
Gael #86
49,079 births · Peak 2024

Nationwide names with similar peak year or record span

Two nationwide peer axes for Theo: closest SSA peak year, and closest first→latest record span. Distinct from the spelling and current-rank neighborhoods above.

Peak year is the single SSA year with the most births for that name; record span is first-to-latest year in the national files, not a recommendation or shared origin claim.

Data Sources

Data as of August 2026. Source: U.S. Social Security Administration (SSA).

According to the Social Security Administration, this profile draws directly from the agency's public-use baby-name files (updated June 2026). See our methodology for the full extraction, aggregation, and privacy-suppression rules.

Primary: Source: U.S. Social Security Administration, Baby Names from Social Security Card Applications, National Data, 1880–2025 (ssa.gov/oact/babynames).

State-level: Source: U.S. Social Security Administration, Baby Names, State-Level Files (namesbystate.zip).

Name Almanac is rendered directly from the Social Security Administration's public baby-name files, no number is typed in by an editor. This profile for Theo draws directly on SSA national and state-level files, no figure is typed in by an editor. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error. Data current as of August 2026.