Cahill
surname · Latin script
Meaning: from Irish Gaelic O Cathail, descendant of Cathal, literally ‘powerful in battle’
(measured from records)Officially recorded in 19 countries · latest register: Census Bureau, 2020
/ˈkɑːhɪl/(recorded in a dictionary) English · from Wiktionary
Cahill is a surname written in the Latin script, with more bearers in the United States than in any other country.
- IEIreland≈1 in 2.5K(inferred from the name graph)
- AUAustralia≈1 in 5.7K
- NZNew Zealand≈1 in 8.3Kfew records
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.
- United States (measured from records)
- Record sources
- 449 (measured from records)
- ≈1 in 2.5K (inferred from the name graph)
20,623 people, 2010
corpus datasets behind its best-documented spelling
strongest: highest-authority source
Ireland, est.
measured from records inferred from the name graph
Meaning & origin
(measured from records)from Irish Gaelic O Cathail, descendant of Cathal, literally ‘powerful in battle’.
Cited for this meaning 1
- Encyclopedia of surnames [the complete companion to tracing your names history]
Attested in 1 language in the etymology graph.
Where in the world
(measured from records)Cahill 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 | — | 20,623 | 1 in 16K | 21K | Cahill | 449 |
| GB United Kingdom | #933 | ≈7,900 est. | ≈1 in 8.8K | listed | Cahill | 194 |
| AU Australia | #562 | ≈4,800 est. | ≈1 in 5.7K | 1 | Cahill | 173 |
| CA Canada | — | ≈3,400 est. | ≈1 in 12K | — | Cahill | 176 |
| IE Ireland | #155 | ≈2,100 est. | ≈1 in 2.5K | listed | Cahill | 128 |
| NZ New Zealand | #878 | ≈640 est. | ≈1 in 8.3K | — | Cahill | 56 |
20,623 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; the hanks-dictionary-surnames-1988 register; SA BDM — Popular baby names South Australia (1944–present); the irish-family-names-grehan-1993 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)Cahill is also recorded in 4 other lexicons, as a different name or as an ordinary word. These are senses of the spelling, not of the name above.
In English, MacCathail, from Cathal ‘valour’; sept in south Galway, later spread to Munster, especially counties Tipperary, Galway and Clare; 10th-century O’Cahill martyr
as a nameIrish family names
dant of Cathal', a personal name composed of the protoCelt. elements cad battle + valos powerful, mighty. Var.: O’Cahill. 89 Caldicott
as a nameA dictionary of surnames
cendant of CathaV, a personal name composed of the proto-Celt, elements cad battle + valos powerful, mighty.
as a nameThe Oxford Names Companion - The definitive guide to Surnames, First Names, and Place Names of the British Isles
In sco, an eel net
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)- Thaddeus Cahillb. 1867USAmerican inventor (1867–1934)
- James Cahillb. 1926USart historian
- Martin Cahillb. 1949IEIrish mob boss (1949–1994)
- Darren Cahillb. 1965AUAustralian tennis player and coach
- Eddie Cahillb. 1978USAmerican actor
- Tim Cahillb. 1979AUAustralian association football player
- Mike Cahillb. 1979USAmerican film director, screenwriter and producer
- Erin Cahillb. 1980USAmerican actress
- Gary Cahillb. 1985GBEnglish association football player (born 1985)
- Sally Cahillb. 2000CAAmerican actress
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)32 registers and reference works attest this spelling, across 19 countries.
| Country | Register | Year | Count | Rank |
|---|---|---|---|---|
| US United States | Census Bureau — Surname Frequency 2010 | 2010 | 21K | #1,737 |
| US United States | Census Bureau — Surname Frequency 2000 | 2000 | 20K | #1,625 |
| US United States | Census Bureau — Surname Frequency 2020 | 2020 | 20K | #1,738 |
| GB United Kingdom | A Dictionary of Surnames (Hanks & Hodges, 1988) | — | — | — |
| IE Ireland | Irish Family Names (Grehan, 1993) | — | — | — |
| US United States | wru Name Dictionary — US surnames, Census 2010 subset (Khanna et al.) | — | — | — |
Reference works 4
- The Oxford Dictionary of Family Names in Britain and Ireland
- Nederlandse FamilienamenBank (Dutch surname bank; ex-Meertens Instituut, now CBG)2007
- Wikipedia surname 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 2026-10-09 data build.
Frequently asked questions
- What does the name Cahill mean, and where does it come from?
- from Irish Gaelic O Cathail, descendant of Cathal, literally ‘powerful in battle’. Recorded by Encyclopedia of surnames [the complete companion to tracing your names history].
- How do you pronounce Cahill?
- In English /ˈkɑːhɪl/ (Wiktionary).
- In which country does Cahill have the most bearers?
- In the United States, the national register counted about 21 thousand people named Cahill, more than in any other country we hold, where it is most often spelled cahill.
- How common is the name Cahill?
- In the United States, the national register counted 20,623 people named Cahill in 2010, about 1 in 16 thousand residents.
- How common is Cahill compared with other names?
- In Ireland, Cahill is the 155th most common surname of 73,729 surnames recorded there.
What do you want to know about Cahill?
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/cahillThe 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, “Cahill” — the 155th most common surname in Ireland. Data snapshot 2026-10-13.