| 9 ago 2026 | Venkatesan, Kavin 2297 | O`cuilleanain, Oisin 2128 | ½-½ | E60 Defensa India de Rey: Fianchetto Variation | The 105th Irish Championship 2026 | Championship | 41 | Ver |
| 8 ago 2026 | O`cuilleanain, Oisin 2128 | Liu, Jason 2161 | ½-½ | A15 Apertura Inglesa: Anglo-Indian Defense, King's Indian Formation, Double Fianchetto | The 105th Irish Championship 2026 | Championship | 45 | Ver |
| 7 ago 2026 | Freeman, Gordon 2068 | O`cuilleanain, Oisin 2128 | 0-1 | A48 Ataque Torre: Fianchetto Defense | The 105th Irish Championship 2026 | Championship | 27 | Ver |
| 6 ago 2026 | O`cuilleanain, Oisin 2128 | Ivanov, Andrey A. 2085 | 0-1 | C00 Defensa Francesa: King's Indian Attack | The 105th Irish Championship 2026 | Championship | 49 | Ver |
| 5 ago 2026 | Tureshbayev, Anuar 2250 | O`cuilleanain, Oisin 2128 | 1-0 | B90 Defensa Siciliana: Najdorf Variation, English Attack | The 105th Irish Championship 2026 | Championship | 39 | Ver |
| 4 ago 2026 | O`cuilleanain, Oisin 2128 | Woods, Yannick 2118 | 1-0 | B90 Defensa Siciliana: Najdorf Variation | The 105th Irish Championship 2026 | Championship | 31 | Ver |
| 3 ago 2026 | Daly, Colm 2182 | O`cuilleanain, Oisin 2128 | 0-1 | D91 Defensa Grünfeld: Three Knights Variation, Petrosian System | The 105th Irish Championship 2026 | Championship | 59 | Ver |
| 1 jun 2026 | Melaugh, Shane 2223 | O`cuilleanain, Oisin 2206 | 0-1 | D37 Gambito de Dama rehusado: Three Knights Variation | 35th Drogheda Chess Congress | Thomson Masters | 41 | Ver |
| 26 abr 2026 | O`cuilleanain, Oisin 2177 | Arun, Nitish 2227 | 1-0 | E15 Defensa India de Dama: Fianchetto Variation, Nimzowitsch Variation | Irish National Club Championship 2026 | 56 | Ver |
| 25 abr 2026 | Delaney, Killian 2306 | O`cuilleanain, Oisin 2177 | ½-½ | B22 Defensa Siciliana: Alapin Variation | Irish National Club Championship 2026 | 25 | Ver |
| 19 abr 2026 | Gkavardinas, Antonios 2286 | O`cuilleanain, Oisin 2177 | 1-0 | B90 Defensa Siciliana: Najdorf Variation, Petronić Attack | 4th Pafos International 2026 | 71 | Ver |
| 15 abr 2026 | Sofronie, Iulian 2355 | O`cuilleanain, Oisin 2177 | 1-0 | A06 Apertura Zukertort | 4th Pafos International 2026 | 21 | Ver |
| 14 abr 2026 | Nikolov, Momchil 2412 | O`cuilleanain, Oisin 2177 | 1-0 | B91 Defensa Siciliana: Najdorf Variation, Zagreb Variation | 4th Pafos International 2026 | 35 | Ver |
| 8 mar 2026 | O`cuilleanain, Oisin 2171 | Melaugh, Shane 2214 | 0-1 | A13 Apertura Inglesa: Agincourt Defense | Cavan Chess Congress 2026 Masters | 50 | Ver |
| 8 mar 2026 | Bartczak, Korneliusz 2120 | O`cuilleanain, Oisin 2171 | 0-1 | B51 Defensa Siciliana: Moscow Variation | Cavan Chess Congress 2026 Masters | 53 | Ver |
| 7 mar 2026 | O`cuilleanain, Oisin 2171 | Artemenko, Oleg 2313 | ½-½ | B36 Defensa Siciliana: Accelerated Dragon, Maróczy Bind | Cavan Chess Congress 2026 Masters | 35 | Ver |
| 22 feb 2026 | O`cuilleanain, Oisin 2164 | Hushpit, Lukian 2100 | ½-½ | C84 Apertura Española (Ruy López): Closed, Martinez Variation | DCU Open 2026 | 73 | Ver |
| 1 feb 2026 | O`cuilleanain, Oisin 2164 | O`Gorman, Alice 2010 | 1-0 | B91 Defensa Siciliana: Najdorf Variation, Zagreb Variation | Sligo 2026 Weekender Masters | 37 | Ver |
| 3 dic 2025 | Hariharan, Shambavi 2020 | O`cuilleanain, Oisin 2171 | ½-½ | E61 Defensa India de Rey | 2025 London Chess Classic | FIDE Open | 53 | Ver |
| 2 dic 2025 | Gurevich, Artjom 2163 | O`cuilleanain, Oisin 2171 | 0-1 | E11 Defensa Bogoindia: Retreat Variation | 2025 London Chess Classic | FIDE Open | 65 | Ver |
