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Thái

Thái, also written Cai. Attested in United States of America, France, Spain, Belgium, Denmark, borne by about 12,006 people in the registers this map holds.

Also written

A person linked these — Wikidata's «said to be the same as», or a family archive that worked it out from documents.

Cai

The same name, spelt two ways

One systematic substitution — s for z, w for v, ch for h — where BOTH spellings are independently attested surnames. Kosina and Kozina are one man in two clerks' handwriting. Stronger than sounding alike, weaker than somebody having checked.

ThayTai

Only sounds alike

An algorithm's guess. Useful for casting a net, and not evidence.

ThaThiTaaiThaoThauThoi

What Wikidata says this name is

Copied from Wikidata, not worked out here. It is crowd-sourced and wrong in places, which is why the item is linked below rather than the claim simply repeated.

  • Vietnamese the language of the name

    Which is not where a family is from. A Polish surname can be borne by people whose forebears never saw Poland, and often is.

Q112175501 on Wikidata ↗ — the item every line above came from.

What Wiktionary says this name is

Copied from the surname template on Wiktionary, not worked out here, and not from its etymology prose. Anyone may edit it; the page and the revision it was read at are linked below.

  • Chinese what the Vietnamese entry says it is from
  • Vietnamese recorded as a surname in these languages

    A language here is the language of the NAME, not a country a family came from — the same caveat the Wikidata section carries, and worth repeating rather than assumed read.

Thái on Wiktionary ↗ — read at revision 89936901. Text from Wiktionary, by its contributors, under CC BY-SA 4.0.

It is also the name of a place

1 place drawn, the largest being TaïTaï — 7,670
Where those places are. A dot is a settlement whose name is this surname, sized by its population — not a claim that anybody of the name lives there. Phonetic neighbours are listed below but not drawn: putting a machine's guess on the ground would dress it up as geography.

This is as close to an origin as this map will go. A surname that is also a place name often came from it — and often did not: plenty are occupations or patronymics that happen to collide with a place, and plenty of places are named after a family rather than the other way round. It is a fact with a source, which is more than an etymology page offers.

  • Taï Côte d'Ivoire pop. 7,670 a spelling of the name

Where it is borne, and where a record names it

Attested in 5 countries: United States of America, France, Spain, Belgium, DenmarkDenmark — attested, not countedBelgium — 21 peopleSpain — 25 peopleFrance — 316 peopleUnited States of America — 11,644 people
A dot is a country, not a place. It sits at the country's centre because a national register counts a country; nothing here says where in it these people are. A hollow ring is attested but not counted — Denmark publishes which surnames exist and not how many carry each, and a family archive finds a name without counting heads. Sizing those by a number nobody published would invent it. Blank is not absence. This draws the 5 countries where the eleven registers and eight archives behind this atlas attest the name. Most of the world has no surname register this project can read, and the ones that do and will not are listed with the reason.
Belgium, by commune. 26 people in 4 of Belgium's 565 communes, counted by Statbel. The biggest is Antwerpen with 10. This is the only country here that can be drawn this way — every other register counts a country and stops, so a blank elsewhere is a gap in what states publish, not in the name.
4 places drawn, the largest being Antwerpen, Luik, Brussel, EvereEvere — 5Brussel — 5Luik — 6Antwerpen — 10

Country by country

Each country below can carry up to three different kinds of evidence, and none of them is the same claim. A register is a head-count — a state counted these people. A record is one document naming the surname on that ground, narrower evidence and often much older. And a volume overlapping these dates is a document from the right place and years — never a document known to name this surname. None of the three ever means the name exists in that country and nowhere else, or that it exists nowhere but here.

United States of America

11,644 Borne — a state counted them — Frequently Occurring Surnames from the 2010 Census; Frequently Occurring Surnames from the 2000 Census.

Whose archive to write to

113,297 of 528,875 volumes held for United States of America overlap the 1910s, 1960s, 1970s, 1980s, 1990s and 2000s — the decades Thái is attested here. Too many to list, and this atlas does not know whether any one of them names Thái. The commonest kinds: Probate, land and notarial, Civil registration and vital records, Immigration and emigration, Church and parish registers. See everything this atlas holds for United States of America →

France

316 Borne — a state counted them — Fichier des noms de famille 1891–2000 (INSEE, fichier national).

Whose archive to write to
Attested here, and nothing that survives covers those years

Thái is attested in France in the 1530s, 1930s and 1940s. Not one of the 1,513 volumes this atlas holds for France covers those years — worth knowing before an afternoon is spent on France's shelf rather than after.

Spain

25 Borne — a state counted them — Frecuencia de apellidos, Censos de población (INE).

Whose archive to write to

This atlas has no birth-year evidence for Thái in Spain, so it cannot narrow Spain's 35,936 volumes by date — see Spain's own page for all of it.

Belgium

21 Borne — a state counted them — Family names by municipality, 1 January 2026 (Statbel, TA_POP_LST_2026).

Whose archive to write to

This atlas has no birth-year evidence for Thái in Belgium, so it cannot narrow Belgium's 24,426 volumes by date — see Belgium's own page for all of it.

Denmark

Borne — a state counted them — Navne registreret i Danmark, January 2020 (Danmarks Statistik, republished by Digitaliseringsstyrelsen).

Whose archive to write to

92 of 4,099 volumes held for Denmark overlap the 1940s — the decades Thái is attested here. Too many to list, and this atlas does not know whether any one of them names Thái. The commonest kinds: Civil registration and vital records. See everything this atlas holds for Denmark →

When it was being born, in France

INSEE counts births by surname and decade from the état civil, 1891 to 2000 — the only dated evidence in this dataset. A name that starts at zero and climbs arrived; a name that falls to nothing left, died out, or emigrated, and the decade it stops is the decade to stop searching. It counts births registered in France, so a family that emigrated in 1900 simply stops appearing, which is information rather than a defect. This name's first French births fall in 1941–1950 and its last in 1991–2000.

  • 1891–1900 —
  • 1901–1910 —
  • 1911–1920 —
  • 1921–1930 —
  • 1931–1940 —
  • 1941–1950 4
  • 1951–1960 9
  • 1961–1970 14
  • 1971–1980 33
  • 1981–1990 130
  • 1991–2000 126

Whose archive held that ground, and when

Every surname site can tell you a name is common somewhere. This one also knows which filing system held that ground in which years — and those are the two halves of one question: my people were called this, they were there, so who has the paper, and for which century. A name in Croatia before 1881 may sit in a military series and not a county one; a name in the Netherlands before 1811 has no civil record at all, only a baptism.

This is about the ground, not about your family. A register counting a name in a country says nothing about which village. And these are the pieces of a country this atlas has drawn, which in a large one may be a corner of it — Acadia reaches into Maine and is not a statement about the United States, and Bohemia's ground crosses into Poland. Each region's own page says which ground it covers. Where a country is missing below, nothing covers it yet.

United States of America
France
Belgium
Denmark
  • Denmark 4 eras Denmark–Norway → Denmark, after the loss of Norway → Prussia, then the German Empire → Denmark

No record region is drawn yet for Spain — which is a gap in this atlas and not a statement about that country.

Find Thái on the map →

The surname dataset · CC0, and downloadable