Casey is a given name, originally derived from the Irish Gaelic cathasaigh, meaning "vigilant" or "watchful". It can be used as a nickname for the name Cassandra or the initials K.C. It is in use for girls or boys in both the United States, the United Kingdom and other English-speaking countries.
It has ranked among the 1,000 most used names for American boys between 1900 and 1919 and again from 1942 to 2022.
