| Game |
| Result | Moves |
Year |
Event/Locale | Opening |
| 1. I Johannesson vs R Schnabel |
| 0-1 | 33 |
2000 |
Reykjavik op19 | A86 Dutch |
| 2. I Johannesson vs J Fridjonsson |
| 0-1 | 24 |
2000 |
Reykjavik op19 | D02 Queen's Pawn Game |
| 3. J Kleinert vs I Johannesson |
| 1-0 | 43 |
2000 |
Reykjavik op19 | C25 Vienna |
| 4. O Kjartansson vs I Johannesson |
| 0-1 | 48 |
2000 |
Reykjavik op19 | A41 Queen's Pawn Game (with ...d6) |
| 5. I Johannesson vs Larus Knutsson |
| 0-1 | 31 |
2000 |
Reykjavik op19 | A01 Nimzovich-Larsen Attack |
| 6. I Johannesson vs O Hannesson |
| 0-1 | 35 |
2000 |
Reykjavik op19 | A17 English |
| 7. G Valgardsson vs I Johannesson |
 | ½-½ | 16 |
2000 |
Reykjavik op19 | C57 Two Knights |
| 8. M Ulfarsson vs I Johannesson |
| 0-1 | 40 |
2001 |
Jonsson Mem Open | C18 French, Winawer |
| 9. T Thorhallsson vs I Johannesson |
| ½-½ | 41 |
2001 |
Jonsson Mem Open | C17 French, Winawer, Advance |
| 10. I Johannesson vs I Asmundsson |
| ½-½ | 99 |
2001 |
Jonsson Mem Open | B41 Sicilian, Kan |
| 11. I Johannesson vs R Hardarson |
| 1-0 | 32 |
2001 |
Jonsson Mem Open | A56 Benoni Defense |
| 12. L E Johannessen vs I Johannesson |
| ½-½ | 45 |
2001 |
Jonsson Mem Open | A58 Benko Gambit |
| 13. F Olafsson vs I Johannesson |
| 1-0 | 40 |
2001 |
Jonsson Mem Open | A30 English, Symmetrical |
| 14. B Thorsteinsson vs I Johannesson |
| ½-½ | 24 |
2001 |
Jonsson Mem Open | C07 French, Tarrasch |
| 15. I Johannesson vs H Olafsson |
| ½-½ | 26 |
2001 |
Jonsson Mem Open | B30 Sicilian |
| 16. I Johannesson vs B Thorfinnsson |
| ½-½ | 41 |
2001 |
Jonsson Mem Open | B50 Sicilian |
| 17. I Johannesson vs B Thorfinnsson |
| ½-½ | 14 |
2001 |
Jonsson Mem Open | A58 Benko Gambit |
| 18. I Johannesson vs P Charbonneau |
| 0-1 | 48 |
2004 |
Reykjavik Open | B06 Robatsch |
| 19. I Johannesson vs B Jobava |
| ½-½ | 88 |
2004 |
20th European Club Cup | D27 Queen's Gambit Accepted, Classical |
| 20. S Bergsson vs I Johannesson |
 | ½-½ | 5 |
2004 |
Reykjavik Open | C01 French, Exchange |
| 21. Galego vs I Johannesson |
 | ½-½ | 16 |
2004 |
Reykjavik Open | A07 King's Indian Attack |
| 22. I Johannesson vs J Ristoja |
| 0-1 | 71 |
2004 |
20th European Club Cup | A41 Queen's Pawn Game (with ...d6) |
| 23. I Johannesson vs D Arngrimsson |
| ½-½ | 41 |
2004 |
Reykjavik Open | A11 English, Caro-Kann Defensive System |
| 24. I Johannesson vs J Ragnarsson |
| 1-0 | 26 |
2004 |
Reykjavik Open | D11 Queen's Gambit Declined Slav |
| 25. Filippov vs I Johannesson |
| ½-½ | 50 |
2004 |
20th European Club Cup | D73 Neo-Grunfeld, 5.Nf3 |