Maclise was born in Cork, Ireland, the son of Alexander McLish (also known as McLeish, McLish, McClisse or McLise), a tanner or shoemaker, but formerly a Scottish Highlander soldier.
Maclise lahir di Cork, Irlandia, putra dari Alexander McLish (juga dikenal sebagai McLeish, McLish, McClisse or McLise), seorang pengolah kulit atau pembuat sepatu, namun dulunya seorang prajurit Scottish Highlander.