An Irish, Scottish and French surname the Casey family name comes from the Gaelic terms ‘cathasach’ and ‘cathasaigh’ which means watchful and vigilant. The original Irish spelling was O Cathasaigh.

Spelling variations for Casey include O’Casey, Caissie and MacCasey.

The County Cork of Ireland is where the Casey surname began. In England the Casey population is mostly in the city of London and in Lancashire and Yorkshire counties. Scattered across Scotland is the Casey surname. Most Casey families live in Lanarkshire and Midlothian. Many Casey families resettled in Australia in the late 19th century.

Casey families mostly live in New York, Pennsylvania, Ohio, Missouri, Massachusetts, Connecticut, New Jersey and California in the United States.

Famous: James E. Casey (founder of the American Messenger Company), Owen Casey (professional Irish tennis player), Richard Casey (Governor-General of Australia), Silas Casey (Civil War Union Major General), Sean Casey (professional wrestler), Shaun Casey (fashion model), Paddy Casey (Irish singer and songwriter) and Harry Wayne Casey (musician).