# Cassidy (surname)

Source: https://namelineage.com/surname/cassidy/  
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 anglicized from Ó Casaide (“descendant of Caiside”). Caiside is a byname from Irish cas (“curly”) meaning “curly-haired”.

| Field | Value |
|---|---|
| Origin | Irish |
| Type | patronymic, formed from a father’s (or ancestor’s) given name |
| People in the US (2010 Census) | 26,590 |
| US rank (2010) | 1,325 of 162,253 |
| How often | about 1 in every 11,611 people |
| Change since 2000 | +2.2% (26,011 in 2000) |
| Pronunciation | /ˈkæsɪdi/, 3 syllables |
| Variant spellings | Casady, Cassda, Casada, Cassaday, Cassady, Cassedy, Cassiday, Kassidy |

## Etymology

From the Irish surname, Anglicized from Ó Caiside (“descendant of Caiside”), from cas (“curly-haired”).

## Who carries it

Share of people named Cassidy 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) | 93% |
| Black (not Hispanic) | 2.2% |
| Hispanic or Latino (any race) | 2.7% |
| Asian and Pacific Islander | 0.7% |
| American Indian and Alaska Native | 0.4% |
| Two or more races | 1.4% |

## Where

Wikidata records people named Cassidy in the United States, the United Kingdom and Australia.

## People named Cassidy

- Katie Cassidy, American actress and singer (born 1986)
- David Cassidy, American actor and singer (1950–2017)
- Eva Cassidy, American singer (1963–1996)
- Joanna Cassidy, American actress
- Butch Cassidy, American Old West outlaw (1866–1908)
- Bill Cassidy, American physician and politician (born 1957)
- Edward Cassidy, Australian Roman Catholic cardinal (1924–2021)
- Christopher Cassidy, American astronaut (born 1970)
- Raffey Cassidy, British actress
- Ted Cassidy, American actor (1932-1979)
- Jack Cassidy, American actor, director, and singer (1927-1976)
- Michael Cassidy, American actor

and 8 more on Wikidata.

## Similar surnames

Cassady, Casado, Cassity, Casady, Costa, Casto, Cuesta, Cozad, Caicedo, Choquette, Cost, Cossette.

## 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.