Kastor
surname · Latin script
Meaning: from the Roman personal name Castor (meaning ‘beaver’) (Dictionary of American Family Names)
(measured from records)Officially recorded in 13 countries · latest register: Census Bureau, 2020
Kastor is a surname written in the Latin script, with more bearers in the United States than in any other country: 306 people, counted by the Census Bureau in 2010.
- EEEstonia≈1 in 130K(inferred from the name graph)
- SESweden1 in 364K
- DKDenmark1 in 587K
carrying the name, as counted by its national register where one exists and as Mondonomo estimates it elsewhere (marked ≈ and "est." on hover). Countries with no figure are shown too: flat where a national register lists the name without counting it, hatched where only our records hold it. One hue, darker where it is more common; hover a country for its figure.
- United States (measured from records)
- Record sources
- 142 (measured from records)
- ≈1 in 127K (inferred from the name graph)
306 people, 2010
corpus datasets behind its best-documented spelling
strongest: highest-authority source
Estonia, est.
measured from records inferred from the name graph
Meaning & origin
(measured from records)from the Roman personal name Castor (meaning ‘beaver’). It was the name of the patron saint of Koblenz, a 4th century priest and missionary who worked in the area of the Mosel.
Cited for this meaning 1
- Dictionary of American Family Names
Attested across 6 languages in the etymology graph.
Where the surname Kastor is found
(measured from records)Kastor 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 | |||
|---|---|---|---|---|---|
| US United States | 306 | 1 in 1.1M | 320 | Kastor | 142 |
| DE Germany | ≈110 est. | ≈1 in 734K | listed | Kastor | 30 |
| MY Malaysia | ≈110 est. | ≈1 in 311K | — | Kastor | 8 |
| IN India | ≈46 est. | ≈1 in 31M | 29 | Kastor | 3 |
| CA Canada | ≈35 est. | ≈1 in 1.2M | 1 | Kastor | 18 |
| SE Sweden | 28 | 1 in 364K | 28 | Kastor | 7 |
| AT Austria | ≈18 est. | ≈1 in 509K | — | Kastor | 4 |
| EE Estonia | ≈11 est. | ≈1 in 127K | 6 | — | 1 |
| DK Denmark | 10 | 1 in 587K | 10 | — | — |
306 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; Alberta Open Government — Frequency and Ranking of Baby Names by Year and Gender; Skatteverket — Sök hur många som har ett visst namn (living population); Danmarks Statistik — Hvor mange hedder...? (living-population name counts); the in-instate-surnames-bystate register; Statistics Estonia — per-name Population Register counts (nimed). 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)Kastor 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 German, ) Castor: männl. Vom. grie chischen Ursprungs. Nach der griechischen
as a nameDUDEN Lexikon der Vornamen
In Russian, var of Kastorii.
as a wordA Dictionary of Period Russian Names (Wickenden / Goldschmidt 1996)
In Filipino, beaver
as a wordkaikki.org Wiktionary extract (IPA + transliterations)
In Serbo-Croatian, dabar
as a wordSkok, Etimologijski rječnik hrvatskoga ili srpskoga jezika (1971-74)
In Basque, "Gastador" A . v. gastalari .
as a wordOrotariko Euskal Hiztegia (OEH) — General/Historical Basque Dictionary, Euskaltzaindia
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)- Deena Kastorb. 1973USAmerican long distance runner and marathoner
- Werner Kastorb. 2000DEGerman journalist
- Robert KastorFRFrench artist
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)Evidence
(measured from records)24 registers and reference works attest this spelling, across 13 countries.
Register rows as of the 2026-10-09 data build.
Frequently asked questions
- Where does the name Kastor come from?
- from the Roman personal name Castor (meaning ‘beaver’). It was the name of the patron saint of Koblenz, a 4th century priest and missionary who worked in the area of the Mosel. Recorded by Dictionary of American Family Names.
- What does the name Kastor mean?
- Recorded meaning: from the Roman personal name Castor (meaning ‘beaver’).
- Which countries have the most people with the surname Kastor?
- In the United States, the national register counted about 306 people named Kastor, more than in any other country we hold, where it is most often spelled kastor. After it come Germany, Malaysia, India and Canada; the country table on this page ranks them.
- How common is the name Kastor?
- In the United States, the national register counted 306 people named Kastor in 2010, about 1 in 1.1 million residents.
What do you want to know about Kastor?
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/kastorThe 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, “Kastor” — ranked 62396th in the United States (Census Bureau). Data snapshot 2026-10-13.