Theta
Girls' nameMeaning not yet documented
Theta has been given to 402 babies in the U.S. since 1907. It was used fewer than 5 times in 2025, so it doesn't appear in the latest year's list — today it's a genuinely uncommon pick. Its peak year was 1907, with 20 recorded.
Babies named Theta, 2015
1 in 740,000
Theta over time, 1880–2025
Based on births in the U.S. Babies given the name each year. Hover the chart — or focus it and use the arrow keys — for any year. Gaps mean the name was given fewer than 5 times that year; these counts are unpublished.
How common is Theta?
Theta had fewer than 5 recorded uses in 2025, so these figures use 2015, the last year it was published.
- Among all babies, 2015
- 1 in 740,000
- 5 of 3,701,574 births
- Among girls only
- 1 in 357,000
- <0.01% of girls
- Rank, 2015
- Unranked
- Fewer than 5 uses
- Coin-flip room size
- 513,148 kids
- Even odds of a second one
Where Theta sits on the popularity scale
Chance at least one other child shares the name
If the other children were drawn at random from the 2015 national name distribution. Real classrooms cluster by region and community, so treat these as a floor, not a ceiling.
Put another way: gather 513,148 children born in 2015 and it's an even bet that one of them is another Theta. In a class of 30 the chance is Under 1%.
When Thetas were born
Half of everyone ever recorded as Theta was born before 1930 — so the typical Theta is around 95 today.
- Biggest decade
- 1920s
- 25.1% of all use
- Born in the last 25 years
- 1.2%
- Mostly a past generation
- Recorded since 1950
- 66
- People you could plausibly meet
1920s — 25.1% of all recorded uses (101).
Is Theta rising or falling?
Rank movement and count movement can disagree — the number of distinct names in use keeps growing, so a name holding a steady count still slides down the list. Both are shown.
- Rank vs 1 year ago
- —
- Not ranked then
- Rank vs 5 years ago
- New entry
- Not ranked then
- Rank vs 10 years ago
- —
- Not ranked then
- Births vs 10 years ago
- —
- Not published both years
- Share of its own peak
- 0%
- Peak was 1907 (20)
- Years since peak
- 118
- Years
- Year-to-year steadiness
- Shifting
- 23.8% average annual change
Spellings of Theta
Theta is not the most common spelling — Thelma is, with 44.6% against Theta's 0.08%.
Grouped by closeness of spelling (up to two letter changes), same sex, with a floor on all-time use. It catches Sophia/Sofia and Aiden/Ayden, and misses spellings that sound alike but look different, like Sean and Shawn.
Where Theta is used
Across 1910–2025, Theta was most concentrated in Texas — about 1 in — girls, against 1 in 2,456,184 across all states with data.
Most concentrated
- 1Texas1 in —
Shading is the share of that state's recorded girls given this name, not the raw count — otherwise the map would just show which states are biggest. Unshaded states have no published records for this period. U.S. birth records suppress state-year counts below 5; state counts therefore don't add up to the national total. Every state links to its full rankings. Theta has too little recent state data to map, so this covers all years from 1910.
Theta by the numbers
The raw record for each sex the name is used for.
Names similar to Theta
Matched on shared beginnings and endings, similar length, and comparable popularity.
Sibling names for Theta
Names from the same era and popularity tier — the two things that make a sibling set feel deliberate — skipping lookalike spellings and shared initials.