Mac Maoláin was a surname borne by a number of unrelated families in Gaelic Ireland, anciently found in Breifne, Mide, Brega, Connacht and Ulster.
Maelan mac Cathmogha was king of Maigh Seóla (now part of County Galway) at his death in 848, claimed as an ancestor of the southern Ui Briuin family, though historians such as T. F. O'Rahilly thought the connection fictitious.
The townland of Cluain Mhic Mhaolain (meadow of McMullan) in Roscommon immortalises the presence of a collateral surname family there.
The Annals of Ulster sub anno 1018 state "Maolán, mac Eccnígh uí Leochain, tigherna Gaileng & Tuath Luicchne (Luigne) uile, do mharbhadh dona Saithnibh" (Maolán, son of Eccnígh uí Leochain, king of Gaileng and all Luigne, was killed by the Saithne).
MacMullan and McMullen families are recorded in the Barony of Uíbh Echach (Clanna-Rory Irish Genealogical Foundation page 16), as Bishops of the Diocese of Connor and Down with the Bishops seat (the seat of MacMullen) identified as the townland of Cabra, parish of Clonduff, ancient territory of Mac Aenghusa (Magennis), Lords of Iveagh.