Declining since 1998, #541 for girls today.
Popularity of Cassidy since 1968
Babies named Cassidy per year in U.S. Social Security records.
Data table (by decade)
| Decade | Girls | Boys |
|---|---|---|
| 1960s | 5 | 10 |
| 1970s | 523 | 351 |
| 1980s | 3,341 | 1,136 |
| 1990s | 20,659 | 900 |
| 2000s | 21,180 | 481 |
| 2010s | 11,235 | 553 |
| 2020s | 3,905 | 304 |
Meaning & origin
Cassidy entered the U.S. naming charts in 1969 and rose steadily through the 1980s and 1990s, reaching its peak rank of 51st in 1999. Since 1998, however, its popularity has been falling, and by 2025 it sits at rank 541, with about 1 in 2880 newborns receiving the name. The name saw particular favor in states like Colorado, Pennsylvania, and Nevada during its peak. Its Irish surname origin and soft sound made it a classic example of the late-20th-century trend toward unisex surname-names for girls, though it remains occasionally used for boys as well.
Cassidy originated as an Irish surname derived from the Gaelic Ó Caiside, meaning 'descendant of Caiside'. The personal name Caiside likely comes from cas, meaning 'curly-haired'. As a given name, Cassidy began to be used in the United States in the late 20th century, influenced by the popularity of similar surname-names and the 1970s television character Cassidy on 'The Partridge Family'.
Where Cassidy is most popular
Births per 100,000 girls by state. Press play or drag the slider to watch it move across the decades. The lightest shade means too few recorded births.
“Cassidy” around the world
Where Cassidy lands in the latest official birth statistics abroad, matched to the U.S. spelling.
France
20
babies in 2024
Ireland
4
babies in 2025
New Zealand
11
babies in 2025
Sources: INSEE (France) · CSO Ireland (Ireland) · NZ Dept of Internal Affairs (New Zealand).
Nicknames & variants
Nicknames: Cass, Cassie
Sibling names for Cassidy
Names that share Cassidy's style, for a brother or sister.
Names like Cassidy
Names whose popularity has moved with Cassidy's over the last 50 years.
