Mullan, Mullen, Mullin, ó Maoláin, 
A Gaelic surname meaning descendant of Maolán, which personal name meant ‘bald’. It has been anglicised as Mullan, Mullen and Mullin. The surname was adopted by several unidentifiable septs. A leading sept of ó Catháin’s country in Derry. In 1890 Mullan was the seventieth most numerous surname and the estimated number of bearers was 9,800. In that year the surname was chiefly found in Tyrone, Derry, Galway and Antrim. In the United States Mullins is the 330th most numerous surname with an estimated 90,750 bearers, and Mullen is the 869th most numerous surname with an estimated 38,500 bearers.