# Dennehy (surname)

Source: https://namelineage.com/surname/dennehy/  
Publisher: Name Lineage. Counts from the US Census Bureau; origin and etymology from Wiktionary; bearers from Wikidata. Data updated 2026-11-11.

A surname from Irish.

| Field | Value |
|---|---|
| Origin | Irish |
| Type | patronymic, formed from a father’s (or ancestor’s) given name |
| People in the US (2010 Census) | 1,735 |
| US rank (2010) | 16,544 of 162,253 |
| How often | about 1 in every 177,951 people |
| Change since 2000 | +2.3% (1,696 in 2000) |
| Pronunciation | not recorded |
| Variant spellings | Danahy |

## Etymology

Reduced Anglicized form of Irish Ó Duineachdha (“descendant of Duineachaidh”), a personal name whose first element is duine (“human being”).

## Who carries it

Share of people named Dennehy in the 2010 US Census by the Census's own race and ethnicity groups. The Census suppresses a share when the count behind it is small.

| Group | Share |
|---|---|
| White (not Hispanic) | 95% |
| Hispanic or Latino (any race) | 2.8% |
| Asian and Pacific Islander | 0.6% |
| Two or more races | 0.8% |

## Where

Wikidata records people named Dennehy in the United States.

## People named Dennehy

- Brian Dennehy, American actor (1938–2020)
- Elizabeth Dennehy, American actress

## Similar surnames

Denny, Denney, Deane, Dennie, Denn, Deneau, Dunn, Dean, Donahue, Downey, Doan, Dinh.

## How to read these numbers

A Census count is people alive and counted in 2010, not births, and names occurring fewer than 100 times are not published at all. Ethnicity shares are the Census's own categories.