Cayo

surname · Spanish · Latin script

Recorded as a male name· opposite-gender records fall within measured source noise

Cayo is a surname, with more bearers in Brazil than in any other country. It appears chiefly in Spanish and English, written in the Latin script. Recorded meaning: A small island or ledge of rock in the water; a key.

rarermore common
  • BRBrazil1 in 739
  • BOBolivia1 in 1.9K
  • PEPeru1 in 6.7K

carrying the name, one hue, darker where it is more common. Hover a country for its figure.

≈289K

across 6 countries

#809

of 16M given names

2

recorded for this name

Sources
230

206K records

Official registry-verified

1 in 739

Brazil

Spellings & scripts

CaioLatin · Portuguese3.2M records
КайоCyrillic · Russian72 records

Locally spelled Caio in BR Brazil, US United States, GB United Kingdom and 7 more, Caius in FI Finland, CA Canada, AU Australia and 1 more, Gaius in NG Nigeria, SG Singapore, BE Belgium and Cajus in DE Germany.

Spellings marked ● are how people bearing the name write it in our records; ○ marks a model's transliteration. Click a spelling to open its page.

Meaning & origin

A small island or ledge of rock in the water; a key.

Sources 1

  • kaikki.org Wiktionary extract (IPA + transliterations)

Attested across 3 languages in the etymology graph.

Where in the world

Sorted by bearers counted by national registers, records where none counts.

Where Cayo is recorded, by country
CountryMost common spellingSources
BR Brazil#154286,597116K rec.1 in 739287KCaio230
AR Argentina40,82227K rec.7KCayo53
PE Peru36,06043K rec.Cayo65
CL Chile4,350592 rec.1Cayo50
BO Bolivia3,2802.4K rec.Cayo29
EC Ecuador1,68054 rec.32Cayo20
US United States1,2997.2K rec.1 in 256K1.3KCaio194
NG Nigeria1,1682.1K rec.Gaius44
MX Mexico1,0801.2K rec.Cayo33
GB United Kingdom728495 rec.3Caio58
PT Portugal#739712237 rec.listedCaio69
CA Canada615192 rec.5Caius36

Roughly 287K people in Brazil bear this name (about 1 in 739). Estimates project the name's share of our records onto national population, so each is only as good as the record base beside it — the Basis column gives that base; rows marked rest on fewer records than the estimate itself and are order-of-magnitude at best.

Country figures for a list of names, at full precision, are available under licence rather than by scraping this table. How that works.

Languages

  • Spanish88K88%
  • English6.2K6%
  • Portuguese1K1%
  • 7921%
  • Hindi7351%
Show as table
Languages in which the name is recorded
NameRecordsNote
Spanish88,38288%
English6,2316%
Portuguese1,0341%
7921%
Hindi7351%

Language is read off each record's context, not declared by the bearer; a share is of all records for this spelling.

Other names spelled this way

Cayo is also recorded as 3 other names, grouped separately because the records behind them do not connect to the one described above.

  • English surname10K records spelled Cayo5 spellings in the group

    Most recorded in United States, Peru, Philippines, Bolivia

    Languages: English, Dutch

    Also written Ċāȳō

  • French surname1.5K records spelled Cayo3 spellings in the group

    Most recorded in Spain, France, United States, Peru

    Languages: French, Catalan

    Also written Cayô

  • a separate surname970 records spelled Cayo3 spellings in the group

    Most recorded in Ecuador, United States, Bolivia, Peru

    Also written Cayó, Cayô

46 further groups record this spelling and are not listed here.

Grouping is the name graph's, not a register's: two spellings join a group when the evidence links them, so a group is a claim about the records rather than about the people.

Other recorded senses

Cayo is also recorded in 5 other lexicons, as a different name or as an ordinary word. These are senses of the spelling, not of the name above.

  • In Spanish, key (island)

    as a wordkaikki.org Wiktionary extract (IPA + transliterations)

  • In Spanish, Latín Gaius, probablemente 'grajo' o nombre totémico

    as a nameDiccionario etimológico de nombres propios

  • In English, district, Belize

    as a namePronouncing Dictionary of Proper Names

  • From the Latin personal name Caius.

    as a nameA concise dictionary of first names

  • Spanish: from the classical Latin personal name Caius , Gaius , which is of extremely ancient origin and uncertain etymology. It was borne, for example, by the dictator Caius Julius Caesar, and in the early Christian period by numerous saints.

    as a word

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.

Over time

02040601950200052 · 2009

Show as table
Cayo in INEC — Visualizador de Nombres y Apellidos, per-token query API (1900–2024), Ecuador, 1903–2024
Yearrecords
19031
19062
19092
19121
19131
19142
19153
19162
19172
19184
19191
19201
19211
19225
19233
19244
19252
19271
19284
19292
19308
19316
19325
193310
19345
19357
19364
19375
19386
193910
19408
194110
19425
19438
194410
194510
19469
194715
19485
19499
19507
19515
195214
19536
195412
19558
19569
195711
195811
195913
196012
196118
196210
196316
196411
196516
196615
196711
196818
196918
197013
197126
197218
197318
197420
197531
197617
197725
197819
197916
198034
198125
198233
198328
198424
198530
198632
198723
198827
198932
199028
199124
199228
199334
199434
199534
199632
199738
199838
199941
200029
200130
200242
200349
200433
200543
200631
200744
200842
200952
201042
201149
201230
201352
201431
201550
201642
201731
201840
201932
202028
202136
202229
202335
202432

EC INEC — Visualizador de Nombres y Apellidos, per-token query API (1900–2024)115 years between 1903–2024. One register's own figures, never a sum across registers: two registers counting the same people would double them.

Notable people with this name

19201940196019802000Percy Cayo, b. 1937Elsa Cayo, b. 1951Alberto Durant, b. 1951Daniel Córdova Cayo, b. 1965Amiel Cayo Coaquira, b. 1969Bárbara Cayo, b. 1974Fiorella Cayo, b. 1975Stephanie Cayo, b. 1988Nathan Cayo, b. 1997Alessia Rovegno, b. 1998

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).

Evidence

Attested in 35 sources across 19 countries.

Official registers attesting Cayo
CountryRegisterYearCountRank
AR ArgentinaRENAPER — Apellidos (person counts, national)7K
BR BrazilIBGE — names by decade (Kaggle mirror)20222.7K
BR BrazilIBGE — Censo 2022 Nomes no Brasil per-token lookup (v3 API, given+surname)2.7K#4,128
BR BrazilIBGE — names by decade (Kaggle mirror)20202.6K
EC EcuadorINEC — Visualizador de Nombres y Apellidos, per-token query API (1900–2024)2.2K
BR BrazilIBGE — names by decade (Kaggle mirror)20101.8K
BR BrazilIBGE — Nomes (census name API)1.4K#7,518
BR BrazilBrasil.IO genero-nomes (IBGE Censo 2010 mirror, CC-BY-SA)1.4K#3,039
BR BrazilIBGE — Censo 2022 Nomes no Brasil per-token lookup (v3 API, given+surname)20001K
US United StatesCensus Bureau — Surname Frequency 20202020807#30,865
BR BrazilIBGE — names by decade (Kaggle mirror)2000805
US United StatesCensus Bureau — Surname Frequency 20102010785#29,918

Reference works 2

  • Wikipedia given-name tokens
  • Wikidata name items (native-script + romanized given/family names)

These works list the name; their figures are licensed and are not reproduced here.

Register rows as of the 2026-09-12 data build · 316 rows in the corpus for this spelling.

Frequently asked questions

How common is the name Cayo?
We estimate roughly 289 thousand people bear Cayo (counting its spellings and scripts) across 6 countries in our records.
In which country does Cayo have the most bearers?
We estimate about 287 thousand people bear Cayo in Brazil, more than in any other country in our records, where it is most often spelled caio.
Where is Cayo most common?
Cayo is densest in Brazil, where the national register counts about 1 in 739 people carrying it.
How common is Cayo compared with other names?
In Brazil, Cayo is the 154th most common given name of 536,280 given names recorded there.
What does the name Cayo mean?
Recorded meaning: A small island or ledge of rock in the water; a key.
Query this name via API
curl https://api.mondonomo.ai/api/v1/name-graph/cayo

The same payload this page is built from: spellings and scripts, countries and languages, related names, and the registers that attest the form. Rate-limited for casual use. Bulk access and licensing.

About this data

measured from records inferred from the name graph machine-generated

Data snapshot . Figures are rebuilt periodically and will change.

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, “Cayo” — the 154th most common given name in Brazil. Data snapshot 2026-09-12.

See how Cayo parses inside a full name →