| Apr 1, 2026 | Halldorsson | 0–1 | Petrovskiy | X Open Semana Santa 2026 - Grupo A | Sicilian Defense: Moscow Variation | |
| Oct 19, 2025 | Halldorsson | 0–1 | Steinberg | Round 1: Halldorsson, Halldor - Steinberg, Nitzan | Sicilian Defense: Moscow Variation | |
| Jul 11, 2025 | Paquico Rodriguez | * | Halldorsson | Round 7: Paquico Rodriguez, Ivan - Halldorsson, Halldor | ? | |
| Jul 10, 2025 | Halldorsson | * | Bendayan Claros | Round 6: Halldorsson, Halldor - Bendayan Claros, Aaron | ? | |
| Jul 9, 2025 | Deruelle Sala | * | Halldorsson | Round 5: Deruelle Sala, Albert - Halldorsson, Halldor | ? | |
| Jul 8, 2025 | Halldorsson | * | Krasteva | Round 4: Halldorsson, Halldor - Krasteva, Beloslava | ? | |
| Jul 7, 2025 | Csiki | * | Halldorsson | Round 3: Csiki, Endre - Halldorsson, Halldor | ? | |
| Jul 6, 2025 | Halldorsson | * | Mellado Sais | Round 2: Halldorsson, Halldor - Mellado Sais, Carles | ? | |
| Apr 20, 2025 | Halldorsson | 1–0 | Lascar | Round 9: Halldorsson, Halldor - Lascar, Radoslawa | Sicilian Defense: Nyezhmetdinov-Rossolimo Attack | |
| Apr 19, 2025 | Peraza Concepcion | 0–1 | Halldorsson | Round 8: Peraza Concepcion, Airam - Halldorsson, Halldor | Modern Defense | |
| Apr 18, 2025 | Halldorsson | 0–1 | Gonzalez Perdomo | Round 7: Halldorsson, Halldor - Gonzalez Perdomo, Sergio | Sicilian Defense: Nyezhmetdinov-Rossolimo Attack | |
| Apr 17, 2025 | De La Cruz Perez | ½–½ | Halldorsson | Round 6: De La Cruz Perez, Carlos - Halldorsson, Halldor | Neo-Grünfeld Defense: Delayed Exchange Variation | |
| Apr 16, 2025 | Halldorsson | 0–1 | Barski | Round 5: Halldorsson, Halldor - Barski, Radoslaw | Sicilian Defense: Nyezhmetdinov-Rossolimo Attack | |
| Apr 15, 2025 | Bangiev | 0–1 | Halldorsson | Round 4: Bangiev, Katharina - Halldorsson, Halldor | Sicilian Defense: Accelerated Dragon | |
| Apr 14, 2025 | Halldorsson | 1–0 | Sanchez Ramirez | Round 3: Halldorsson, Halldor - Sanchez Ramirez, Gustavo | Scandinavian Defense: Main Line | |
| Apr 13, 2025 | Petriashvili | 1–0 | Halldorsson | Round 2: Petriashvili, Nikoloz - Halldorsson, Halldor | King's Indian Attack: Symmetrical Defense | |
| Apr 12, 2025 | Halldorsson | 1–0 | Rodriguez Trujillo | Round 1: Halldorsson, Halldor - Rodriguez Trujillo, Cristian | Ruy Lopez: Closed, Worrall Attack | |
| Oct 1, 2023 | Yilmaz | 1–0 | Halldorsson | European Chess Club Cup 2023 | English Opening: Anglo-Indian Defense, Anglo-Grünfeld Variation | |
