Castro

surname · Latin script

Meaning, in Spanish: fort, fortified settlement

Recorded for both men and women· direction only, no split published

/kastɾo/(machine-generated) pronunciation, model-generated

Castro is a surname written in the Latin script, with more bearers in the Philippines than in any other country, where it is the 31st most common surname.

rarermore common
  • ECEcuador1 in 136(measured from records)
  • SVEl Salvador≈1 in 174
  • COColombia≈1 in 241

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.

Philippines (inferred from the name graph)

≈240,000 people, est.

#150 (measured from records)

of 19M surnames

3 (measured from records)

recorded for this name

Sources
511 (measured from records)

Highest-authority source

1 in 65 (inferred from the name graph)

Costa Rica

measured from records inferred from the name graph

Name dossier (print, CSV)

Spellings & scripts(measured from records)

CastroLatin(measured from records)
КастроCyrillic(measured from records)
ΚαστροGreek(measured from records)

One other spelling is counted as the same name:

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)

Person who lives by or in a castle or walled town, or person from Castro; from castro 'castle, walled town'.

Sources 1

  • Encyclopedia of surnames [the complete companion to tracing your names history]

Attested across 12 languages in the etymology graph.

How Castro is read(measured from records)

Castro is one spelling over 3 language communities, and the dictionaries record it differently in 3 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.

  • Spanish58%

    fort, fortified settlement

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

  • Portuguese15%

    fort (of Roman or prehistoric origin)

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

  • English14%

    Person who lives by or in a castle or walled town, or person from Castro; from castro 'castle, walled town'.

    as a nameEncyclopedia of surnames [the complete companion to tracing your names history]

    Fidel, president, Cuba

    as a namePronouncing Dictionary of Proper Names

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)

Castro 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.

Where Castro is recorded, by country
CountryMost common spellingSources
PH Philippines#31≈240,000 est.≈1 in 451—Castro159
CO Colombia#21≈200,000 est.≈1 in 241183Castro215
US United States#403184,1341 in 1.8K188KCastro511
AR Argentina#29148,2161 in 307148KCastro165
PE Peru#31≈120,000 est.≈1 in 257357KCastro145
EC Ecuador—123,8851 in 136124KCastro119
CR Costa Rica—78,7551 in 6579K—142
UY Uruguay—40,0261 in 8540K—113
SV El Salvador#33≈37,000 est.≈1 in 174—Castro98

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: RENAPER — Apellidos (person counts, national); RENIEC — DNI population names; Census Bureau — Surname Frequency 2010; Census Bureau — Surname Frequency 2020; the co-datosgov-candidates register; INEC — civil registry names; TSE — electoral roll (padrón) names; INE Uruguay — Apellidos más frecuentes 1902–2024 (Tableau Public). 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 names spelled this way(inferred from the name graph)

Castro is also recorded as 4 other names, grouped separately because the records behind them do not connect to the one described above.

  • English surname40 spellings in the group

    Most recorded in United States, Philippines, United Kingdom, Canada

    Languages: English, German, Dutch

    Also written Castró, Cäströ, Cástro, Castro', Čäströ

  • a separate name3 spellings in the group

    Also written Cástro

  • English surname55 spellings in the group

    Most recorded in United States, Philippines, Laos, United Kingdom

    Languages: English, Lao, Thai

    Also written Castor, Cäströ, คาสโตร์, คาสโตร, C'Astro

  • Indonesian surname3 spellings in the group

    Most recorded in Philippines, Indonesia, United States, Peru

    Languages: Indonesian, Malay

    Also written Častro

89 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(measured from records)

Castro 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.

  • In Italian, numerous places so called, from LL castellio, gen. castellibnis, fortified town or village (a deriv. of castellum; see dic): topographic name for someone living by a castle or walled town, from It., Sp., Port, castro (L castrum legion¬ ary camp), or habitation name from a place named with this element. Castle) . Vars.: It.: Castri, Lo Cast(r)o, Licastri, De Castri(s).

    as a nameA dictionary of surnames

  • In Italian, do lat. castrum, fortificação/cidadela; oriundo de localidades chamadas Castro

    as a nameDicionário dos sobrenomes italianos

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)

1850190019502000Ángel Castro y Arguíz, b. 1875Fidel Castro, b. 1926Raúl Castro, b. 1931Juanita Castro, b. 1933Verónica Castro, b. 1952Alfredo Castro, b. 1955Xiomara Castro, b. 1959Itziar Castro, b. 1977Gonzalo Castro Randon, b. 1987Jesús Ferreira, b. 2000

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)

FormalEstimado/a Castro,Dear Castro, (English)
InformalEstimado/a Castro,Hello, (English)

Evidence(measured from records)

Attested in 72 sources across 36 countries.

Official registers attesting Castro
CountryRegisterYearCountRank
PE PeruRENIEC — DNI population names2019357K#17
PE PeruRENIEC — Apellidos más frecuentes (national DNI bearer counts, 2025)2025256K#32
US United StatesCensus Bureau — Surname Frequency 20202020188K#130
US United StatesCensus Bureau — Surname Frequency 20102010184K#138
AR ArgentinaRENAPER — Apellidos (person counts, national)—148K—
US United StatesCensus Bureau — Surname Frequency 20002000133K#194
EC EcuadorINEC — civil registry names2024124K#10
CR Costa RicaTSE — electoral roll (padrón) names—79K#11
UY UruguayINE Uruguay — Apellidos más frecuentes 1902–2024 (Tableau Public)—40K—
EC EcuadorINEC — Visualizador de Nombres y Apellidos, per-token query API (1900–2024)20241.2K—
CO ColombiaColombia — Función Pública SIGEP II public-servant name corpus (datos.gov.co)—183#14
CR Costa RicaTSE — Consulta de nombres (Padrón Nacional Electoral name enumeration)———

Reference works 8

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

Where does the name Castro come from?
Person who lives by or in a castle or walled town, or person from Castro; from castro 'castle, walled town'. Recorded by Encyclopedia of surnames [the complete companion to tracing your names history].
How do you pronounce Castro?
A machine transcription gives /kastɾo/ (IPA) for Spanish.
What does the name Castro mean?
In Spanish, fort, fortified settlement
In which country does Castro have the most bearers?
Mondonomo estimates about 242 thousand people named Castro in the Philippines, more than in any other country we hold, where it is most often spelled castro.
Where is Castro most common?
Measured as a share of residents rather than as a count, Castro is densest in Costa Rica — about 1 in 65 people — even though Philippines holds more of our records for it.
How common is the name Castro?
In the United States, the national register counted 184,134 people named Castro in 2010, about 1 in 1.8 thousand residents.
How common is Castro compared with other names?
In the Philippines, Castro is the 31st most common surname of 876,464 surnames recorded there.

What do you want to know about Castro?

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Query this name via API
curl -H "X-API-Key: YOUR_KEY" https://api.mondonomo.ai/api/v1/name-graph/castro

The 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, “Castro” — the 31st most common surname in Philippines. Data snapshot 2026-10-10.

See how Castro parses inside a full name →