Cassidy

Meaning and origin

The last name Cassidy is of Irish origin and derives from the Gaelic surname "Ó Caiside" or "Mac Caiside," meaning "descendant or son of Caiside." The name Caiside comes from the personal name Caiside, which was originally a byname meaning "curly-haired" in Gaelic. The name has ancient roots and is associated with County Fermanagh in Northern Ireland. Over time, variations of the name emerged, including Cassaday, Cusack, and Cusick, as the Cassidy clan spread throughout Ireland and beyond.

The longer story

The last name Cassidy is of Irish origin and is derived from the Gaelic surname Ó Caiside. This surname is believed to have originated from the personal name Caiside, which means "curly-haired" or "curly-headed" in Irish. The prefix "Ó" indicates "descendant of," making Cassidy mean "descendant of Caiside."

The surname Cassidy is predominantly found in Ireland, especially in the counties of Fermanagh and Donegal. It is also common in Scotland and England, where it may have been brought by Irish immigrants.

Migration and emigration patterns have led to the spread of the Cassidy surname beyond Ireland. As Irish immigrants settled in different parts of the world, particularly the United States, the name became established in those regions as well. Today, Cassidy is a relatively common surname in the United States, with concentrations in states like New York, Pennsylvania, and California.

Surname origins are rarely settled: one spelling can have several sources, and families often took a name for reasons nobody wrote down. Check it against the sources below before you rely on it.