Koji
given name · Latin script
Meaning, in Japanese: Rōmaji transcription of こじ
Recorded as a male name· opposite-gender records fall within measured source noise
/ˈkoʊdʒi/(machine-generated) pronunciation, model-generated
Koji is a given name written in the Latin script, with more bearers in Japan than in any other country, where it is the 35th most common given name.
- JPJapan≈1 in 612(inferred from the name graph)
- USUnited States1 in 269K
- HKHong Kong≈1 in 54K
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.
- Japan (inferred from the name graph)
- 2 (measured from records)
- Sources
- 195 (measured from records)
- ≈1 in 612 (inferred from the name graph)
≈210,000 people, est.
recorded for this name
Highest-authority source
Japan, est.
measured from records inferred from the name graph
Spellings & scripts(measured from records)
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(measured from records)
Rōmaji transcription of こじ
Sources 1
- kaikki.org Wiktionary extract (IPA + transliterations)
Attested across 16 languages in the etymology graph.
How Koji is read(measured from records)
Koji is one spelling over 2 language communities, and the dictionaries record it differently in 2 of them. Each row is what a source recorded for that language, beside the share of this name’s records the language holds. No single row is the name’s meaning.
- Japanese85%
Rōmaji transcription of こじ
as a wordkaikki.org Wiktionary extract (IPA + transliterations)
- English6.7%
A substance that is produced by letting a mold, especially Aspergillus oryzae, grow on rice, barley, soybeans, etc., used to make fermented products such as sake, amazake, miso, and soy sauce.
as a wordkaikki.org Wiktionary extract (IPA + transliterations)
The share is ours — how much of this name’s records each language holds. The sense beside it is the source’s, quoted and credited, including where it names a gender. We do not publish a gender of our own per language: our records carry one figure for the spelling as a whole.
Where in the world(measured from records)
Koji 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.
| Country | Most common spelling | Sources | ||||
|---|---|---|---|---|---|---|
| JP Japan | #35 | ≈210,000 est. | ≈1 in 612 | listed | Koji | 182 |
| CN China | — | ≈9,600 est. | ≈1 in 145K | — | Koji | 22 |
| US United States | — | 1,237 | 1 in 269K | 1.2K | Koji | 195 |
| NG Nigeria | — | ≈880 est. | ≈1 in 242K | — | Koji | 7 |
| BR Brazil | — | 245 | 1 in 864K | 245 | — | 1 |
| TW Taiwan | — | ≈200 est. | ≈1 in 119K | — | Koji | 20 |
| HK Hong Kong | — | ≈130 est. | ≈1 in 54K | — | Koji | 16 |
| SG Singapore | — | ≈97 est. | ≈1 in 64K | — | Koji | 31 |
| EE Estonia | — | ≈21 est. | ≈1 in 59K | listed | — | 6 |
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: the japanese-names-oneill-1972 register; Census Bureau — First Name Frequency 2020 by sex; IBGE — names by decade (Kaggle mirror); the ee-siseministeerium-registry register. 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)
Koji is also recorded in 2 other lexicons, as a different name or as an ordinary word. These are senses of the spelling, not of the name above.
‘Filial ruler’; ‘happy second [son)’.
as a nameA concise dictionary of first names
In Serbo-Croatian, which, what
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.
Notable people with this name(measured from records)
- Kōji Yakushob. 1956JPJapanese actor (1956-)
- Kōji Morimotob. 1959JPJapanese anime director
- Koji Kondob. 1961JPJapanese composer and pianist (born 1961)
- Kōji Tsujitanib. 1962JPJapanese actor, voice actor, narrator and director of audiography
- Kōji Yamamurab. 1964JPJapanese independent animator
- Kōji Kikkawab. 1965JPJapanese singer-songwriter, actor
- Kōji Imadab. 1966JPJapanese actor
- Kōji Murofushib. 1974JPJapanese hammer thrower, university professor (physical education), commissioner of the Japan sports agency
- Kouji Wadab. 1974JPnot in their usual nameJapanese singer (1974-2016)
- Koji Setob. 1988JPJapanese actor singer
The ten people covered by the most Wikipedia language editions — a proxy for cross-cultural notability, which favours historical and Western figures over equally prominent contemporary ones — shown by birth year. Source: Wikidata (CC0).
How to address them(machine-generated)
A formal English salutation is built on the surname, so it needs a full name — on its own, a first name only supports the informal form.
Evidence(measured from records)
Attested in 37 sources across 20 countries.
| Country | Register | Year | Count | Rank |
|---|---|---|---|---|
| US United States | Census Bureau — First Name Frequency 2020 by sex | 2020 | 1.2K | #10,668 |
| BR Brazil | IBGE — names by decade (Kaggle mirror) | 2022 | 245 | — |
| BR Brazil | IBGE — Censo 2022 Nomes no Brasil per-token lookup (v3 API, given+surname) | — | 242 | #21,979 |
| BR Brazil | Brasil.IO genero-nomes (IBGE Censo 2010 mirror, CC-BY-SA) | — | 237 | #10,394 |
| BR Brazil | IBGE — names by decade (Kaggle mirror) | 1960 | 220 | — |
| BR Brazil | IBGE — Nomes (census name API) | — | 184 | #26,504 |
| BR Brazil | IBGE — names by decade (Kaggle mirror) | 1950 | 150 | — |
| BR Brazil | IBGE — names by decade (Kaggle mirror) | 1940 | 89 | — |
| BR Brazil | IBGE — Censo 2022 Nomes no Brasil per-token lookup (v3 API, given+surname) | 1950 | 70 | — |
| BR Brazil | IBGE — names by decade (Kaggle mirror) | 1930 | 64 | — |
| BR Brazil | IBGE — Censo 2022 Nomes no Brasil per-token lookup (v3 API, given+surname) | 1940 | 61 | — |
| US United States | SSA — National Baby Names (1880–present) | 2025 | 34 | — |
Reference works 4
- Dictionary of American Family Names
- Wikipedia given-name tokens
- Wikipedia surname tokens
- Ethiopian name tokens (GitHub lehagere/ethiopian-names, 40/60 condominium list)
These works list the name; their figures are licensed and are not reproduced here.
Register rows as of the 2026-10-09 data build.
Frequently asked questions
- What does the name Koji mean, and where does it come from?
- Rōmaji transcription of こじ Recorded by kaikki.org Wiktionary extract (IPA + transliterations).
- Is Koji a male or female name?
- Koji is a male name in our records. Opposite-gender entries fall within the cross-gender noise we measure in the source data, so we don't report them as usage.
- How common is the name Koji?
- In the United States, the national register counted 1,237 people named Koji in 2020, about 1 in 269 thousand residents.
- How common is Koji compared with other names?
- In Japan, Koji is the 35th most common given name of 366,905 given names recorded there.
- How do you pronounce Koji?
- A machine transcription gives /ˈkoʊdʒi/ (IPA) for Japanese.
- In which country does Koji have the most bearers?
- Mondonomo estimates about 205 thousand people named Koji in Japan, more than in any other country we hold, where it is most often spelled koji.
What do you want to know about Koji?
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/kojiThe 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, “Koji” — the 35th most common given name in Japan. Data snapshot 2026-10-10.