| Game |
| Result | Moves |
Year |
Event/Locale | Opening |
| 1. B Jonsson vs O Jonsson |
| 1-0 | 35 |
2009 |
Reykjavik Open | D32 Queen's Gambit Declined, Tarrasch |
| 2. O Jonsson vs P Andrason |
| 1-0 | 24 |
2009 |
Reykjavik Open | B77 Sicilian, Dragon, Yugoslav Attack |
| 3. T Struch vs O Jonsson |
| 1-0 | 59 |
2009 |
Politiken Cup | C69 Ruy Lopez, Exchange, Gligoric Variation, 6.d4 |
| 4. O Jonsson vs P Magnusson |
| 1-0 | 23 |
2009 |
Reykjavik Open | B40 Sicilian |
| 5. M Naslund vs O Jonsson |
| 1-0 | 47 |
2009 |
Reykjavik Open | D11 Queen's Gambit Declined Slav |
| 6. O Jonsson vs S Peschardt |
 | 1-0 | 25 |
2009 |
Politiken Cup | B32 Sicilian |
| 7. B J Kristinsson vs O Jonsson |
| ½-½ | 59 |
2009 |
Reykjavik Open | D46 Queen's Gambit Declined Semi-Slav |
| 8. O Jonsson vs R Hardarson |
| 0-1 | 68 |
2009 |
Reykjavik Open | C55 Two Knights Defense |
| 9. O Jonsson vs J Thomassen |
| 0-1 | 27 |
2009 |
Politiken Cup | B94 Sicilian, Najdorf |
| 10. O Jonsson vs O Thorsson |
| 0-1 | 53 |
2009 |
Reykjavik Open | B48 Sicilian, Taimanov Variation |
| 11. O Jonsson vs J Kvisla |
| 0-1 | 51 |
2009 |
Politiken Cup | B28 Sicilian, O'Kelly Variation |
| 12. O Jonsson vs G Gudmundsdottir |
| 1-0 | 24 |
2009 |
Reykjavik Open | C10 French |
| 13. S Bjornsson vs O Jonsson |
| 1-0 | 51 |
2009 |
Reykjavik Open | D10 Queen's Gambit Declined Slav |
| 14. J M Nielsen vs O Jonsson |
| 1-0 | 30 |
2009 |
Politiken Cup | A45 Queen's Pawn Game |
| 15. E Sigurdarson vs O Jonsson |
| 0-1 | 30 |
2010 |
Reykjavik Open | B22 Sicilian, Alapin |
| 16. J Johannsdottir vs O Jonsson |
| 0-1 | 23 |
2010 |
Reykjavik Open | B22 Sicilian, Alapin |
| 17. O Jonsson vs V Ni |
| 0-1 | 40 |
2010 |
Reykjavik Open | B42 Sicilian, Kan |
| 18. O Jonsson vs T Olafsson |
| 0-1 | 44 |
2010 |
Reykjavik Open | E60 King's Indian Defense |
| 19. D Arngrimsson vs O Jonsson |
| 1-0 | 58 |
2010 |
Reykjavik Open | B22 Sicilian, Alapin |
| 20. D Kjartansson vs O Jonsson |
| ½-½ | 34 |
2010 |
Reykjavik Open | A22 English |
| 21. O Jonsson vs J Bick |
| 0-1 | 40 |
2010 |
Reykjavik Open | A43 Old Benoni |
| 22. O Jonsson vs M Ocantos |
| 0-1 | 28 |
2010 |
Reykjavik Open | A46 Queen's Pawn Game |
| 23. S Unnarsson vs O Jonsson |
| 0-1 | 36 |
2010 |
Reykjavik Open | B62 Sicilian, Richter-Rauzer |
| 24. E Reppen vs O Jonsson |
| ½-½ | 64 |
2011 |
Reykjavik Open | C50 Giuoco Piano |
| 25. O Jonsson vs J Halldorsson |
| 0-1 | 60 |
2011 |
Reykjavik Open | D04 Queen's Pawn Game |