Mac Amhalghaidh is an Irish masculine surname. The name translates into English as "son of Amhalghadh". The surname originated as a patronym, however it no longer refers to the actual name of the bearer's father. The form of the surname for unmarried females is Nic Amhalghaidh. The forms for married females are Bean Mhic Amhalghaidh and Mhic Amhalghaidh. The Irish Mac Amhalghaidh has numerous Anglicised forms. The surname has been borne by at least one notable Irish family.