Issue of Hugh McManus O'Donnell (Aodh mac Maghnusa Ó Domhnaill; c. 1520 - 1600)^{[lower-roman 1]}

First marriage: (Unknown woman)

• Duncan "Scaite" O'Donnell (Donnchadh Ó Domhnaill)^{[lower-roman 2]}

• Rory O'Donnell (Ruaidhri Ó Domhnaill)
  • Died 1575

• Donnell O'Donnell (Domhnall Ó Domhnaill)
  • Died 14 September 1590^{[lower-roman 3]}
    • Married a daughter of Turlough Lynagh O'Neill around c. 1589^{[lower-roman 4]}
      • Donnell Oge O'Donnell (fl. 1607)^{[lower-roman 5]}

• Unnamed daughter
  • Married a son of Turlough Lynagh O'Neill

• Joanna O'Donnell (Siobhán Ní Domhnaill)^{[lower-greek 1]}
  • Died c. January 1591^{[lower-greek 2][lower-roman 7][lower-roman 6][lower-roman 9][lower-roman 10][lower-roman 11]}
    • Married Hugh O'Neill, Earl of Tyrone on 14 June 1574^{[lower-roman 9][lower-roman 7][lower-roman 8]} - marriage repudiated in 1579^{[lower-roman 12]} - later reconfirmed^{[lower-roman 13]}
      • Margaret O'Neill^{[lower-roman 14][lower-roman 11][lower-roman 8]}
        • Married Richard Butler, 3rd Viscount Mountgarret^{[lower-roman 11][lower-roman 8]}
      • Sarah O'Neill (fl. 1595-1602)^{[lower-greek 3][lower-roman 8][lower-roman 7]}
        • Married Sir Arthur Magennis^{[lower-roman 11][lower-roman 8]} before 4 March 1595^{[lower-roman 8]}
      • Mary O'Neill (fl. 1608)^{[lower-roman 7][lower-roman 8]}
        • Married Brian McHugh Og MacMahon^{[lower-roman 8]}
      • Alice O'Neill (1583 - c. 1665)^{[lower-roman 15][lower-roman 16][lower-roman 7][lower-roman 17][lower-greek 4]}
        • Married Randal MacDonnell, 1st Earl of Antrim^{[lower-roman 15][lower-roman 18][lower-roman 7][lower-roman 19]}
      • Hugh O'Neill (1585 - 24 September 1609)^{[lower-roman 20][lower-roman 7][lower-roman 8][lower-roman 21]}
      • Henry O'Neill (c. 1586^{[lower-roman 22]} - c. 1620^{[lower-greek 5]})

Second marriage, c. 1569: Fiona MacDonald (Fionnghuala Nic Dhomhnaill, also known as Iníon Dubh; fl. 1567–1611), daughter of James MacDonald, 6th of Dunnyveg and Agnes Campbell.^{[lower-roman 23][lower-roman 8]}

• Hugh Roe O'Donnell (Aodh Ruadh Ó Domhnaill)
  • Born October 1572,^{[lower-roman 24][lower-roman 25][lower-roman 26][lower-greek 6]}
  • Died 10 September 1602^{[lower-roman 27]}
    • Betrothed to Rose O'Neill in c. 1587^{[lower-roman 24][lower-roman 8]} - married in December 1592^{[lower-roman 7]} - separated in 1595^{[lower-roman 24][lower-roman 8]}

• Rory O'Donnell (Ruaidrí Ó Domhnaill)
  • Born 1575^{[lower-roman 28][lower-roman 29][lower-roman 30]}
  • Died 28 July 1608^{[lower-roman 28][lower-roman 29][lower-roman 30]}
    • Married Bridget FitzGerald of Kildare in c. December 1606^{[lower-roman 29][lower-roman 30]}
      • Hugh Albert O'Donnell (October 1606 - 1642)^{[lower-roman 31][lower-roman 32][lower-roman 33]}
      • Mary Stuart O'Donnell (c. 1607 - after 1639)^{[lower-roman 28][lower-roman 34][lower-roman 31]}
      • Some sources incorrectly suggest that there is an elder daughter named Elizabeth (see Elizabeth_Plunket#Errors in her genealogy)

• Nuala O'Donnell (Nuala Ní Domhnaill)
  • Born c. 1576^{[lower-roman 35][lower-roman 36]}
  • Died c. 1630^{[lower-roman 37][lower-roman 38]}
    • Married Niall Garve O'Donnell in 1591^{[lower-roman 38]} - separated 1600^{[lower-roman 39][lower-roman 38]}
      • Naghtan O'Donnell (fl. 1608)^{[lower-roman 40][lower-roman 41][lower-roman 42]}
      • A son (c. 1596 - 1600)^{[lower-roman 43][lower-roman 44]}
      • Grania O'Donnell (fl. 1607 - 1617)^{[lower-roman 45][lower-roman 40]}

• Manus O'Donnell (Maghnus Ó Domhnaill)
  • Born c. 1579^{[lower-roman 46]}
  • Died 22 October 1600^{[lower-roman 47]}

• Margaret O'Donnell (Mairghead Ní Domhnaill)
  • fl. 1608, possibly died 1662

• Mary O'Donnell (Máire Ní Domhnaill)
  • Died 1662
    • Married Donnell Ballagh O'Cahan in c. 1593^{[lower-roman 48][lower-roman 49]}
      • Rory Oge O'Cahan^{[lower-roman 48]}
      • A daughter^{[lower-roman 48]}
    • Married Teigue O'Rourke in 1599^{[lower-roman 50]}
      • Brian O'Rourke^{[lower-roman 50]}

• Caffar O'Donnell (Cathbarr Ó Domhnaill)
  • Born c. 1583^{[lower-roman 25]}
  • Died 15 September 1608^{[lower-roman 51]}
    • Married Rosa O'Doherty^{[lower-roman 51]}
      • Hugh O'Donnell (c. June 1605 - 1625)^{[lower-roman 51][lower-roman 52]}
    • Relationship with an unmarried woman^{[lower-roman 51]}
      • Conn O'Donnell (fl. 1608-1629)^{[lower-roman 51]}

• Gráinne O'Donnell (Gráinne Ní Domhnaill)^{[lower-roman 53]}