Cahill is an Irish surname and given name, derived from the Gaelic 'Ó Cathaoil', which means 'descendant of Cathal'. It is believed to have originated in County Kerry, where it was once a numerous sept (clan). The name Cahal itself comes from the Irish 'Cathal', meaning 'battle' or 'chief'. In its anglicized form, Cahill has been associated with various notable figures throughout history, including Irish politicians and sportspeople.
The number of births with the name Cahill experienced some variation over these years, peaking at 6 births in 2001 and totaling 16 across this period.