MallowbyNames

Theory

THEER-ee · A modern coinage derived from the English word 'theory', meaning a supposition or system of ideas.

2025 rank (girls)
#5,917
Babies named in 2025
20
Peak popularity
2023
2025 frequency
1 in 80,363 girls
Usually for
Girls & boys
Trend
Rising since 2010

Rising since 2010, #5,917 for girls today.

Popularity of Theory since 2006

Babies named Theory per year in U.S. Social Security records.

7132020102020Most births 2023GirlsBoys
GirlsBoys
Data table (by decade)
DecadeGirlsBoys
2000s56
2010s6028
2020s10058

Meaning & origin

Theory is a modern word name that first entered the U.S. naming database in 2006. It is a rare choice, ranked 5,917 in 2025, with approximately 1 in 80,363 newborns receiving the name. Its popularity peaked in 2023, and it has been rising since 2010, reflecting a broader trend of abstract noun names like Lyric, Sage, and Story. While Theory is used for both boys and girls, it skews female in practice. The name has not appeared in any top state lists, indicating its usage is scattered across the country. As a vocabulary name, its meaning is directly accessible, making it appealing to parents drawn to intellectual or philosophical concepts. Without a long history or notable bearers, Theory remains a distinctive and unconventional choice.

Theory is a modern word name adopted from the English vocabulary word 'theory', which itself comes from Late Latin 'theoria' and Greek 'theōria' meaning contemplation or speculation. It first appeared as a given name in the United States in 2006 and has gradually gained usage, primarily for girls but also for boys, reflecting a trend of abstract noun names. Its rise in popularity may be influenced by cultural figures like the R&B singer The-Dream (born Terius) and the television show 'The Big Bang Theory', though no direct connection is established.

Nicknames & variants

Nicknames: Thea, Ree

Sibling names for Theory

Names that share Theory's style, for a brother or sister.

Sisters: Astrid, Lyric, Nova, Olive, Sage

Brothers: Atlas, Crew, Finn, Jude, Reid

A parent animal hugging its little one, the personalized name page

T is for Theory, our favorite little person.

T is for Theory…”

In a Mallowby alphabet book, Theory's letter becomes Theory's page: hand-illustrated, printed hardcover or paperback, made just for them.

Make Theory's book

Books for siblings or grandkids? The second book is 15% off.

Questions parents ask

What does the name Theory mean?
Theory is a modern word name taken directly from the English word 'theory', meaning a supposition or system of ideas intended to explain something.
How popular is the name Theory?
Theory is not common. As of 2025, it ranked 5,917 in the U.S., with about 1 in 80,363 newborns given the name. Its peak popularity was in 2023.
Is Theory a boy's or girl's name?
Theory is used for both boys and girls, though it is more often given to girls. The U.S. data lists it as unisex.