This Mayo surname has many variants listed in the 1847-64 ‘Valuation’ of households in Ireland compiled by Sir Richard Griffith. These variants include O’ Mally, O’ Melia, Malley, Maley, Mailey, Mealey and Mally. By far the most numerous forms were Malley (722) followed by O’Malley (109).

The only counties where the name was very numerous were Mayo, Galway and to some extent, Donegal and Limerick:

  • Mayo: Malley (482). O’Malley (53)
  • Galway: Malley (57). O’Malley (23)
  • Donegal: Malley (36)

A separate (genealogically speaking) family inhabited Limerick and its environs. In Griffith’s ‘Valuation’ they occur under Malley with 32 households.

The occasional variant Melia, used in Connacht, has diminished in numbers in modern times.

During the modern period where the resumption of the prefix ‘O’ has taken place, many of the contemporary descendants of the above people would be ‘O’Malley’; this, however, would not hold for many individuals in the USA, who would still go by the surname denuded of its prefix.

O’ Malley Current Frequencies: USA 7173, GB 3341, Ireland 3839

The origin of the personal name from which the surname is derived is uncertain. Woulfe suggests an ancient Celtic source, maglios ‘prince, champion, poet’. Other possibilities include epithets mall ‘slow’ or málla ‘affable, sedate, pleasant, stately’. Often the most ancient names have an uncertain etymology.

The main source of the surname was the two Mayo chiefdoms of the Umhalls, the baronies of Burrishoole and Murresk. This family was renowned as seafarers, commanding a considerable navy, which controlled the seas off the province of Connacht. They frequently troubled the intrusive English vessels, particularly in the person of Grace O’Malley (Gráinne Ní Mháille, c. 1530- c. 1603 ), who appeared with her retinue at the Court of Elizabeth 1st, and was treated by the latter at Greenwich Palace with all due deference owed to visiting dignitaries.

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