Mael Isa Mac Mael Coluim (died Good Friday, 1136) was described upon his death as "chief keeper of the calendar of Ard-Macha, its chief antiquary and librarian". By the 19th century the surname appears to have been rendered as McCollum. The Abbot of Armagh at this time was , a member of the , while the Archbishop of Armagh was Máel Máedóc Ua Morgair.