| Families |
Ethnic Group |
Branch of |
| Haldane, Hadden |
Normans |
|
| Hamilton |
Normans |
|
| Handrahan |
|
O'Hanrahan |
| Hanratty |
|
O'Hanraghty |
| Hare |
|
MacGarry |
| Hare |
IVL - Ireland |
|
| Haren, Harhan |
|
O'Hanrahan |
| Haren, Harhan |
IVL - Clare, Connacht, Oriel |
|
| Hart |
IVL - Ulster, South Scotland |
|
| Hay |
|
O'Hea |
| Hay |
IVL - Ireland |
|
| Hay |
Normans |
|
| Hearne |
|
O'Aherne |
| Heas |
|
O'Hea |
| Henchy |
|
O'Hennessy |
| Henderson |
|
Gunn |
| Henderson |
|
MacKeown |
| Henderson |
IVL - West Scotland |
|
| Henry |
|
MacNaughton |
| Henry |
IVL - South Scotland |
|
| Hewison |
|
MacDonald (Clan Donald) |
| Hiffernan, Hernon |
|
O'Heffernan |
| Holland |
|
O'Houlihan |
| Horan, Haughran |
|
O'Hanrahan |
| Hylan |
|
O'Phelan |
| Hynes |
|
O'Heyne |
| Inches |
|
Robertson |
| Innes |
|
MacInnes |
| Innes |
IVL - Ireland |
|
| Innes |
Normans |
|
| Innie |
|
Innes |
| Isles |
|
MacDonald (Clan Donald) |
| Jameson |
|
Gunn |
| Jameson |
IVL - West Scotland |
|
| Jennings |
Normans |
Burke |
| Johnson |
|
Gunn |
| Johnson |
|
Maclan (Glencoe) |
| Johnson |
|
Maclan (Ardnamurchan) |
| Johnson |
Gaels |
O'Neill (Ulster) |
| Jordan |
IVL - Ireland |
|
| Jordan |
Normans |
|
| Joy |
|
Joyce |
| Joy |
IVL - Ireland |
|
| Joyce |
Normans |
Tribes of Galway |
| Kane |
|
O'Cahan |
| Kavanagh |
Laigin |
|
| Kay |
|
Davidson |
| Kealaghan |
IVL - Oriel |
|
|
