| Game |
| Result | Moves |
Year |
Event/Locale | Opening |
| 1. R Soupizon vs H Halldorsson |
| 1-0 | 17 |
2000 |
Reykjavik op19 | B23 Sicilian, Closed |
| 2. A Schmitz vs H Halldorsson |
| 1-0 | 29 |
2000 |
Reykjavik op19 | B22 Sicilian, Alapin |
| 3. H Halldorsson vs H Palsson |
| 0-1 | 21 |
2000 |
Reykjavik op19 | B13 Caro-Kann, Exchange |
| 4. H Halldorsson vs K Edvardsson |
| 0-1 | 41 |
2000 |
Reykjavik op19 | C78 Ruy Lopez |
| 5. T E Wiley vs H Halldorsson |
| 1-0 | 32 |
2000 |
Reykjavik op19 | D85 Grunfeld |
| 6. H Halldorsson vs J Ragnarsson |
| ½-½ | 24 |
2000 |
Reykjavik op19 | B13 Caro-Kann, Exchange |
| 7. O Hannesson vs H Halldorsson |
| ½-½ | 17 |
2000 |
Reykjavik op19 | B90 Sicilian, Najdorf |
| 8. Stefan Arnalds vs H Halldorsson |
| 0-1 | 32 |
2000 |
Reykjavik op19 | D89 Grunfeld |
| 9. H Halldorsson vs M Schmitz |
| ½-½ | 29 |
2000 |
Reykjavik op19 | C15 French, Winawer |
| 10. H Halldorsson vs T Nyback |
| 0-1 | 38 |
2001 |
Jonsson Mem Open | B30 Sicilian |
| 11. H Halldorsson vs G Gislason |
| ½-½ | 36 |
2001 |
Jonsson Mem Open | B51 Sicilian, Canal-Sokolsky (Rossolimo) Attack |
| 12. B Thorfinnsson vs H Halldorsson |
| 0-1 | 39 |
2001 |
Jonsson Mem Open | D92 Grunfeld, 5.Bf4 |
| 13. B Thorsteinsson vs H Halldorsson |
| ½-½ | 41 |
2001 |
Jonsson Mem Open | B92 Sicilian, Najdorf, Opocensky Variation |
| 14. H Halldorsson vs S Kristjansson |
| ½-½ | 53 |
2001 |
Jonsson Mem Open | C02 French, Advance |
| 15. P Thorarinsson vs H Halldorsson |
| 1-0 | 66 |
2001 |
Jonsson Mem Open | A15 English |
| 16. H Halldorsson vs A Karason |
| ½-½ | 53 |
2001 |
Jonsson Mem Open | B51 Sicilian, Canal-Sokolsky (Rossolimo) Attack |
| 17. H Halldorsson vs H Baldursson |
| 1-0 | 30 |
2001 |
Jonsson Mem Open | B06 Robatsch |
| 18. A Gunnarsson vs H Halldorsson |
 | 1-0 | 66 |
2001 |
Jonsson Mem Open | A16 English |
| 19. G Palmason vs H Halldorsson |
| 1-0 | 44 |
2001 |
Jonsson Mem Open | A15 English |
| 20. B Thorfinnsson vs H Halldorsson |
 | 1-0 | 29 |
2004 |
Reykjavik Open | A48 King's Indian |
| 21. T Bromann vs H Halldorsson |
| 1-0 | 41 |
2004 |
Reykjavik Open | A48 King's Indian |
| 22. H Halldorsson vs Carlsen |
| 0-1 | 67 |
2004 |
Reykjavik Open | B52 Sicilian, Canal-Sokolsky (Rossolimo) Attack |
| 23. H Halldorsson vs F Handke |
| ½-½ | 31 |
2004 |
Reykjavik Open | B54 Sicilian |
| 24. Stefansson vs H Halldorsson |
| 1-0 | 39 |
2004 |
Icelandic Team Championship | D74 Neo-Grunfeld, 6.cd Nxd5, 7.O-O |
| 25. P Lehikoinen vs H Halldorsson |
| 0-1 | 26 |
2004 |
Reykjavik Open | B99 Sicilian, Najdorf, 7...Be7 Main line |