| Feb 10, 2024 | Tom Wills | 0–1 | Conor O'Donnell | 4NCL Division 1 2023-2024 | Sicilian Defense: Nyezhmetdinov-Rossolimo Attack | |
| Jan 28, 2024 | Oisin O'Cuilleanain | ½–½ | Conor O'Donnell | Round 5: Oisin O'Cuilleanain - Conor O'Donnell | Caro-Kann Defense: Two Knights Attack, Mindeno Variation, Exchange Line | |
| Jan 28, 2024 | Conor O'Donnell | 1–0 | Santiago Suarez Hernan | Round 4: Conor O'Donnell - Santiago Suarez Hernan | King's Indian Attack | |
| Jan 27, 2024 | Adam Collins | ½–½ | Conor O'Donnell | Round 3: Adam Collins - Conor O'Donnell | Catalan Opening: Open Defense | |
| Jan 27, 2024 | Conor O'Donnell | ½–½ | Emils Steiners | Round 2: Conor O'Donnell - Emils Steiners | Sicilian Defense: Lasker-Pelikan Variation | |
| Jul 10, 2022 | Conor O'Donnell | 1–0 | Peter Carroll | Round 9: Conor O'Donnell - Peter Carroll | English Opening: Anglo-Indian Defense, Queen's Indian Formation | |
| Jul 9, 2022 | Conor O'Donnell | 0–1 | Colm Daly | Round 8: Conor O'Donnell - Colm Daly | French Defense: Advance Variation | |
| Jul 8, 2022 | Conor O'Donnell | ½–½ | Henry Li | Round 7: Conor O'Donnell - Henry Li | King's Indian Defense: Four Pawns Attack | |
| Jul 7, 2022 | Alexander Baburin | ½–½ | Conor O'Donnell | Round 6: Alexander Baburin - Conor O'Donnell | Bogo-Indian Defense: Retreat Variation | |
| Jul 6, 2022 | Tarun Kanyamarala | ½–½ | Conor O'Donnell | Round 5: Tarun Kanyamarala - Conor O'Donnell | Queen's Gambit Accepted: Classical Defense, Main Line | |
| Jul 5, 2022 | Conor O'Donnell | 1–0 | Diana Mats | Round 4: Conor O'Donnell - Diana Mats | Sicilian Defense: Accelerated Dragon, Maróczy Bind | |
| Jul 4, 2022 | Joe Ryan | ½–½ | Conor O'Donnell | Round 3: Joe Ryan - Conor O'Donnell | Caro-Kann Defense: Endgame Variation | |
| Jul 3, 2022 | Conor O'Donnell | ½–½ | Tom O'Gorman | Round 2: Conor O'Donnell - Tom O'Gorman | Nimzo-Indian Defense: Classical Variation | |
| Jul 2, 2022 | Peter Cafolla | 0–1 | Conor O'Donnell | Round 1: Peter Cafolla - Conor O'Donnell | French Defense: Advance Variation, Euwe Variation | |
| Mar 27, 2022 | Conor O'Donnell | ½–½ | Nicholas Pert | 4NCL Main League 1-2 | Nimzo-Indian Defense: Normal Variation | |
| Mar 20, 2022 | Conor O'Donnell | ½–½ | Keith Arkell | Round 9: Conor O'Donnell - Keith Arkell | Scandinavian Defense: Gubinsky-Melts Defense | |
| Mar 20, 2022 | Conor E. Murphy | 1–0 | Conor O'Donnell | Round 8: Conor E. Murphy - Conor O'Donnell | Queen's Gambit Declined: Exchange Variation, Positional Variation | |
| Mar 19, 2022 | Trisha Kanyamarala | ½–½ | Conor O'Donnell | Round 7: Trisha Kanyamarala - Conor O'Donnell | Dutch Defense: Leningrad Variation, Warsaw Variation | |
| Mar 19, 2022 | Conor O'Donnell | 1–0 | Peter Carroll | Round 6: Conor O'Donnell - Peter Carroll | Zukertort Opening | |
| Mar 18, 2022 | Kavin Venkatesan | ½–½ | Conor O'Donnell | Round 5: Kavin Venkatesan - Conor O'Donnell | Nimzo-Indian Defense: Kmoch Variation | |
| Mar 18, 2022 | Conor O'Donnell | ½–½ | Colm Daly | Round 4: Conor O'Donnell - Colm Daly | English Opening: Agincourt Defense, Catalan Defense, Semi-Slav Defense | |
| Mar 17, 2022 | Tarun Kanyamarala | 1–0 | Conor O'Donnell | Round 3: Tarun Kanyamarala - Conor O'Donnell | Indian Defense | |
| Mar 17, 2022 | Conor O'Donnell | 1–0 | Adam Collins | Round 2: Conor O'Donnell - Adam Collins | Caro-Kann Defense: Advance Variation | |
| Aug 8, 2021 | Leon Putar | 0–1 | Conor O'Donnell | Round 9: Leon Putar - Conor O'Donnell | Zukertort Opening: Sicilian Invitation | |
| Aug 7, 2021 | Conor O'Donnell | 1–0 | Kavin Venkatesan | Round 8: Conor O'Donnell - Kavin Venkatesan | English Opening: Anglo-Indian Defense | |
| Aug 6, 2021 | Colm Daly | 1–0 | Conor O'Donnell | Round 7: Colm Daly - Conor O'Donnell | Indian Defense: Spielmann-Indian | |
| Aug 5, 2021 | Conor O'Donnell | 0–1 | Mark Heidenfeld | Round 6: Conor O'Donnell - Mark Heidenfeld | French Defense: Rubinstein Variation, Blackburne Defense | |
| Aug 4, 2021 | David Fitzsimons | ½–½ | Conor O'Donnell | Round 5: David Fitzsimons - Conor O'Donnell | Caro-Kann Defense: Exchange Variation | |
| Aug 4, 2021 | Conor O'Donnell | 1–0 | Tarun Kanyamarala | Round 4: Conor O'Donnell - Tarun Kanyamarala | English Opening: Agincourt Defense, Catalan Defense Accepted | |
| Aug 4, 2021 | Alexander Baburin | ½–½ | Conor O'Donnell | Round 3: Alexander Baburin - Conor O'Donnell | Queen's Pawn Game: London System | |
| Aug 4, 2021 | Conor O'Donnell | 1–0 | Kevin O'Flaherty | Round 2: Conor O'Donnell - Kevin O'Flaherty | French Defense: Franco-Hiva Gambit | |
| Aug 4, 2021 | Rudolf Tirziman | 0–1 | Conor O'Donnell | Round 1: Rudolf Tirziman - Conor O'Donnell | Semi-Slav Defense: Noteboom Variation | |
| Aug 29, 2020 | Lara Janzelj | 0–1 | Conor O'Donnell | Offerspill Nordic Invitational – Round 9: Lara Janzelj - Conor O'Donnell | English Opening: Caro-Kann Defensive System | |
| Aug 28, 2020 | Conor O'Donnell | 0–1 | Ludvig Carlsson | Offerspill Nordic Invitational – Round 8: Conor O'Donnell - Ludvig Carlsson | Slav Defense: Modern Line | |
| Aug 27, 2020 | Conor O'Donnell | 1–0 | Ellen Fredericia Nilssen | Offerspill Nordic Invitational – Round 7: Conor O'Donnell - Ellen Fredericia Nilssen | English Opening: Anglo-Indian Defense, Anglo-Grünfeld Variation | |
| Aug 26, 2020 | Mathias Unneland | 0–1 | Conor O'Donnell | Offerspill Nordic Invitational – Round 6: Mathias Unneland - Conor O'Donnell | Nimzowitsch Defense: Williams Variation | |
| Aug 25, 2020 | Conor O'Donnell | 0–1 | Jonas Buhl Bjerre | Offerspill Nordic Invitational – Round 5: Conor O'Donnell - Jonas Buhl Bjerre | Nimzo-Indian Defense: Three Knights Variation | |
| Aug 24, 2020 | Tor Fredrik Kaasen | ½–½ | Conor O'Donnell | Offerspill Nordic Invitational – Round 4: Tor Fredrik Kaasen - Conor O'Donnell | French Defense: Steinitz Variation, Boleslavsky Variation | |
| Aug 23, 2020 | Mads Vestby-Ellingsen | ½–½ | Conor O'Donnell | Offerspill Nordic Invitational – Round 3: Mads Vestby-Ellingsen - Conor O | French Defense: Steinitz Variation, Boleslavsky Variation | |