Boys' name · peaked in 2023
Theo name popularity since 1925
35,829 babies born in the US from 1925 to 2025 were named Theo (4.6% girls, 95.4% boys). Half of them were born in 2021 or earlier, so the typical Theo is about 5 years old in 2026. Theo peaked in 2023 as the #78 name for boys, and it ranked #82 in 2025.
Key facts
- US babies since 1925
- 35,829
- Named Theo, 1925–2025
- In 2025
- #82
- for boys in 2025 (3,945 babies)
- Girls / boys
- 95.4% boys
- 1,652 girls · 34,177 boys
- Most popular in
- Utah
- 2.34× its national share
Peak year is the year Theo made up the largest share of US boys, in records going back to 1880. Typical age is based on births from 1925 on, not on who is living today.
Theo births per year, 1925–2025
2023 was the biggest year for Theo both by count and as a share of all babies.
- Fastest rise: Between 2013 and 2018, Theo became 4.4× more common, from 1 in 5,180 baby boys to 1 in 1,170.
Shaded on the chart. This compares Theo's share of all US boys five years apart, counting only years with at least 100 babies named Theo.
Decade by decade
Babies named Theo in each decade, and its rank among boys' names in the middle year of the decade (1935, 1945 … 2025).
| Decade | Girls | Boys | Rank |
|---|---|---|---|
| 1925–29 | 383 | 478 | – |
| 1930s | 365 | 680 | #729 |
| 1940s | 326 | 440 | #941 |
| 1950s | 174 | 371 | #1,337 |
| 1960s | 67 | 323 | #1,161 |
| 1970s | 19 | 386 | #1,124 |
| 1980s | 0 | 540 | #1,063 |
| 1990s | 5 | 600 | #1,646 |
| 2000s | 5 | 1,386 | #1,154 |
| 2010s | 56 | 8,189 | #406 |
| 2020–25 | 252 | 20,784 | #82 |
Ranks count every name given to at least 5 boys that year, so they can go past 1,000.
Generation fingerprint
79.6% of babies named Theo from 1925 to 2025 were born in the Gen Alpha years (2013–2025). The full split by generation:
Where Theo is most popular
The index compares Theo's share of babies in each state with its share nationwide, 1925–2025 (1.50× = 50% more common). States with at least 300 babies named Theo.
| State | Index | Babies |
|---|---|---|
| Utah | 2.34× | 624 |
| Washington | 1.75× | 919 |
| Massachusetts | 1.73× | 1,287 |
| Oregon | 1.71× | 502 |
| Colorado | 1.63× | 629 |
Other spellings
Spellings that sound like Theo and were given to at least 1,000 boys from 1925 to 2025, with the year each one was most popular.
| Spelling | Boys | Peak year |
|---|---|---|
| Theo (this page) | 34,177 | 2023 |
| Teo | 2,987 | 2024 |
Names with a similar story
Of the other 1999 names on this site, these six had the share of babies closest in shape to Theo's from 1925 to 2025, however common each one got. Each line is scaled to its own high; the dashed line is Theo.
Names from the same era
Other common names that peaked within two years of Theo (2023).
Source: U.S. Social Security Administration national and state baby-name data, which covers names given to at least 5 babies of one sex in a year. About the data