It is the Anglicized form of Mac Artáin, denoting the son of Artán (diminutive of the personal name Art, an old Irish word for "bear").

The McCartans belonged to the Uí Echach Cobo—of whom Magennis was the chief family—of the Dál nAraidi, who in turn came from the Cruthin tribe who were the first Celts to arrive in Ireland from about 800 to 500 BC.

The McCartan strongholds included Drumaroad, the adjoining townlands Loughinisland, Drumnaquoile, Magheratimpany, Ardilea, and the neighbouring town of Ballynahinch.

As a family bursting with football endeavors, albeit predominantly within the Gaelic adaptation of the sport, Seamus Vincent McCartan is the clan's single professional player, currently at club level for Bradford City.

Ryan McCartan, portraying the character Digbert "Diggie" Smalls on Disney's Liv and Maddie, has risen to success, showcasing the musical and theatrical talents of the clan.