From the site IRISH MANES
... The Origin of Irish Family Names, a list of the 100 most common names found in Ireland and their meanings


These details were compiled from the 1890 Matheson report

Rank - Name - Gaelic Equivalent - Meaning

1 Murphy - ? Murchadha - sea-battler

2 Kelly - ? Ceallaigh - bright-headed

3 O'Sullivan - ? S?illeabh?in - dark-eyed

4 Walsh - Breathnach - Welshman

5 Smith - Mac Gabhann - son of the smith

6 O'Brien - ? Briain - high, noble

7 Byrne - ? Broin - a raven

8 Ryan - ? Maoilriain - king

9 O'Connor - ? Conchobhair - patron of warriors

10 O'Neill - ? N?ill - from Niall of the Nine Hostages

11 O'Reilly - ? Raghallaigh

12 Doyle - ? Dubhghaill - dark foreigner

13 McCarthy - Mac Carthaigh - loving person

14 Gallagher - ? Gallchobhair - lover of foreigners

15 O'Doherty - ? Dochartaigh - hurtful

16 Kennedy - ? Cinn?ide - helmet headed

17 Lynch - ? Loinsigh - seafarer, exile

18 Murray - ? Muireadhaigh - lord, master

19 Quinn - ? Cuinn - wisdom, chief

20 Moore - ? Mordha - majestic

21 McLoughlin - Mac Lochlainn - viking

22 O'Carroll - ? Cearbhaill - valorous in battle

23 Connolly - ? Conghaile - fierce as a hound

24 Daly - ? D?laigh - assembles frequently

25 O'Connell - ? Conaill - strong as a wolf

26 Wilson - Mac Liam - son of William

27 Dunne - ? Duinn brown

28 Brennan - ? Braon?in - sorrow

29 Burke - de B?rca - from Richard de Burgh

30 Collins - ? Coile?in - young warrior

31 Campbell - crooked mouth

32 Clarke - ?Cl?irigh - clergyman

33 Johnston - Mac Se?in - son of John

34 Hughes - ? hAodha - fire

35 O'Farrell - ? Fearghail - man of valour

36 Fitzgerald - Mac Gearailt - spear rule

37 Brown - Mac an Bhreithi?n - son of the brehon (judge)

38 Martin - Mac Giolla Mh?irt?n - devotee of Saint Martin

39 Maguire - Mag Uidhir - dun-coloured

40 Nolan - ? Nuall?in - famous

41 Flynn - ? Floinn - bright red

42 Thompson - Mac Tom?is - son of Thom

43 O'Callaghan - ? Ceallach?in - bright headed

44 O'Donnell - ? Domhnaill - world-mighty

45 Duffy - ? Dufaigh - dark, black

46 O'Mahony - ? Math?na - bear-calf

47 Boyle - ? Baoill - vain pledge

48 Healy - ? h?alaighthe - artistic, scientific

49 O'Shea - ? S?aghdha - fine, stately

50 White - Mac Giolla Bh?in - of fair complexion

51 Sweeney - Mac Suibhne - pleasant

52 Hayes - ? hAodha - fire

53 Kavanagh Caomh?nach comely, mild

54 Power - de Paor - the poor man

55 McGrath - Mac Craith - son of grace

56 Moran - ? M?r?in - great

57 Brady - Mac Br?daigh - spirited

58 Stewart - Stiobhard - one who superintends

59 Casey - ? Cathasaigh - vigilant in war, watchful

60 Foley - ? Foghladh - a plunderer

61 Fitzpatrick - Mac Giolla Ph?draig - devotee of Saint Patrick

62 O'Leary - ? Laoghaire - calf-herd

63 McDonnell - Mac Domhnaill - world-mighty

64 MacMahon - Mac Math?na - bear-calf

65 Donnelly - ? Donnghaile - brown valour

66 Regan - ? Riag?in - little king

67 Donovan - ? Donnabh?in - brown, black

68 Burns - from Scottish Burness

69 Flanagan - ? Flannag?in - red, ruddy

70 Mullan - ? Maol?in - bald

71 Barry - de Barra - Cambro-Norman name

72 Kane - ? Cath?in - battler

73 Robinson - son of Robert

74 Cunningham - Scottish name

75 Griffin - ? Gr?ofa - Welsh: Gruffudd

76 Kenny - ? Cionaoith - fire sprung

77 Sheehan - O'Siodhachain - peaceful

78 Ward - Mac an Bhaird - son of the bard

79 Whelan - ? Faol?in - wolf

80 Lyons - ? Laighin - grey

81 Reid - red haired, ruddy complexion

82 Graham - grey home

83 Higgins - ? hUiginn

84 Cullen - ? Cuilinn - holly

85 Keane - Mac Cath?in

86 King - ? Cionga

87 Maher - Meagher - fine, majestic

88 MacKenna - Mac Cionaoith - fire-sprung

89 Bell - Mac Giolla Mhaoil

90 Scott - a Scottish gael

91 Hogan - ? h?g?in - young

92 O'Keeffe - ? Caoimh - gentle

93 Magee - Mag Aoidh - fire

94 MacNamara - Mac Conmara - hound of the sea

95 MacDonald - Mac D?naill - world-mighty

96 MacDermott - Mac Diarmada - free from jealousy

97 Molony - ? Maolomhnaigh - servant of the Church

98 O'Rourke - ? Ruairc

99 Buckley - ? Buachalla - cow herd

100 O'Dwyer - ? Dubhuir - black