O-O
surname · Latin script
Recorded for both men and women· direction only, no split published
O-O is a surname written in the Latin script, with more bearers in the United States than in any other country.
- FIFinland1 in 44K(measured from records)
- NONorway1 in 64K
- USUnited States1 in 208K
carrying the name, as counted by its national register where one exists and as Mondonomo estimates it elsewhere (marked ≈ and "est." on hover). One hue, darker where it is more common; hover a country for its figure.
- United States (measured from records)
- Sources
- 41 (measured from records)
- 1 in 44K (inferred from the name graph)
1,601 people, 2010
Highest-authority source
Finland
measured from records inferred from the name graph
Spellings & scripts(measured from records)
One other spelling is counted as the same name:
Locally spelled Oo in US United States, CO Colombia.
Spellings marked ● are how people bearing the name write it in our records, and ○ marks a model's transliteration; click a spelling to open its page.
Meaning & origin
No verified etymology recorded for this name yet — the entries below are drawn from usage statistics and the name graph.
Where in the world(measured from records)
O-O counted together with the spellings and other-language forms grouped with it. Where a register counted another spelling, the row names it.
Sorted by bearers: national registers' counts, and Mondonomo's estimates (≈, est.) where no register counts.
1,601 people counted by Census Bureau — Surname Frequency 2010, 2010. Exact figures are national registers' own counts, while figures marked ≈ and est. are Mondonomo’s estimates, counted from our sources and calibrated against those registers; hover one for how far to trust it in that country. A dash means neither exists.
Registers cited: Census Bureau — Surname Frequency 2010; Census Bureau — Surname Frequency 2020; DVV — Nimipalvelu (Finnish name service, per-name lookup); SSB — Navnesøk (name-search service, living population); Danmarks Statistik — Hvor mange hedder...? (living-population name counts). Figures without a register are Mondonomo estimates; see Methodology.
Country figures for a list of names, at full precision, are available under licence rather than by scraping this table (how that works).
Other recorded senses(measured from records)
O-O is also recorded in 3 other lexicons, as a different name or as an ordinary word. These are senses of the spelling, not of the name above.
Alternative form of 0-0 (“kingside castling”).
as a wordkaikki.org Wiktionary extract (IPA + transliterations)
In nkr, your (sg.) several
as a wordAustronesian Comparative Dictionary (ACD), CLDF v2.0
In srn, twin
as a wordkaikki.org Wiktionary extract (IPA + transliterations)
Ordered by how much of this spelling's record each language holds, so a sense from a language the name is barely used in sits last rather than first.
Evidence(measured from records)
No register attests this spelling yet
Frequently asked questions
- In which country does O-O have the most bearers?
- In the United States, the national register counted about 1.6 thousand people named O-O, more than in any other country we hold, where it is most often spelled oo.
- Where is O-O most common?
- Measured as a share of residents rather than as a count, O-O is densest in Finland — about 1 in 44 thousand people — even though United States holds more of our records for it.
- How common is the name O-O?
- In the United States, the national register counted 1,601 people named O-O in 2010, about 1 in 208 thousand residents.
What do you want to know about O-O?
Nobody replies to these one by one, but what readers ask decides what these pages answer next.
Query this name via API
curl -H "X-API-Key: YOUR_KEY" https://api.mondonomo.ai/api/v1/name-graph/o-oThe payload this page is built from: spellings and scripts, countries and languages, related names, and the registers that attest the form. It takes a free API key (1,000 requests a day), which returns what this page shows everyone; the full country table, every register citation and the year-by-year series come with a licensed key, as does bulk access.
About this data
measured from records inferred from the name graph machine-generated
These figures come from the data snapshot of and will change as it is rebuilt.
Statistics are aggregated from the Mondonomo name corpus; related names and etymology are inferred from the name graph; pronunciation and any machine-marked transliterations are model-generated. Read how the numbers are made, including their known failure modes, and where the data comes from.
Reference works we consult — surname dictionaries, official name registers, Wikidata and Wiktionary — are named directly, beside the claims they support. The per-country source counts also include datasets of person records: we publish how many there are and their authority tier, but not their names.
Cite this page Mondonomo, “O-O”. Data snapshot 2026-10-10.