O'Flanagan is a surname of Irish origin, commonly associated with the Gaelic name Ó Flannagáin, which means "descendant of Flannagan." The name is often linked to various regions in Ireland, particularly County Kerry and County Clare. Individuals with the surname O'Flanagan have made contributions in various fields, including literature, politics, and sports. The name is also associated with notable figures such as John O'Flanagan, an Irish architect known for his work in the early 20th century.