The Uí Néill (Irish for "grandsons (descendants) of Niall") were an Irish dynasty who claimed descent from Niall Noigiallach (Niall of the Nine Hostages), a semi-historical High King of Ireland who died about 450.

The first generation of the Uí Néill were his sons, eight in all:

• Conall Gulban
• Endae
• Eogan
• Coirpre
• Lóegaire
• Maine of Tethba
• Conall Cremthainne
• Fiachu

Uí Néill Genealogy

                Conn Cétchathach
                       |
                       |
                 Art mac Cuinn
                       |
                       |
                Cormac mac Airt
                       |
                       |
               Cairbre Lifechair
                       |
                       |
               Fiachu Sraibtine 
                       |
                       |
               Muiredach Tirech
                       |
                       |
               Eochaid Mugmedon
          + Mongfind        + Cairenn 
             |                  |
    _________|_________         |
    |        |        |         |
    |        |        |         |
  Brion  Fiachrae  Ailill     Niall
      (The Connachta)           |
      __________________________|_______________________________________________________
      |          |       |      .      |           |        |             |            |
      |          |       |      .      |           |        |             |            |
Conall Gulban  Endae   Eogan    .   Coirpre    Lóegaire  Maine  Conall Cremthainne  Fiachu
                         |      .      |           |           ________|________
                         |      .      |           |           |               |
                    Muirdeach   . Cormac Caech  Lughaid  Fergus Cerrbel      Ardgal
                         |      .      |        (d.507)        |
                         |      .      |                       |
                  Muirchertach  .   Tuathal                Diarmaid
                    mac Ercae   .   Maelgarb            mac Cearbhaill
                     (d.536)    .   (d.544)                (d.565)
                                .
      (Northern Uí Néill)       .                 (Southern Uí Néill)