Mac Craith (Meic Craith, plural form), meaning "Son of Grace", is an Irish surname, one branch of which is rendered McGrath.
At least two distinct families named Mac Craith lived in medieval Ireland.
The Meic Craith of Thomond were a learned family with close ties to Clare Abbey, an Augustinian foundation.
They were historians and poets of the Uí Bhriain kings and earls of Thomond.
Another family of the name, not known to be related, were natives of Termon McGrath, Lough Erne.