| Game |
| Result | Moves |
Year |
Event/Locale | Opening |
| 1. I Johannsson vs P Papapavlou |
| ½-½ | 20 |
1954 |
Amsterdam ol (Men) | D51 Queen's Gambit Declined |
| 2. I Johannsson vs Geller |
| 0-1 | 73 |
1954 |
Amsterdam | E87 King's Indian, Samisch, Orthodox |
| 3. E Joppen vs I Johannsson |
| 1-0 | 46 |
1954 |
Amsterdam ol (Men) | C73 Ruy Lopez, Modern Steinitz Defense |
| 4. M Rantanen vs I Johannsson |
| 0-1 | 24 |
1954 |
Amsterdam ol (Men) | E90 King's Indian |
| 5. F Zita vs I Johannsson |
| ½-½ | 105 |
1954 |
Amsterdam ol (Men) | D27 Queen's Gambit Accepted, Classical |
| 6. I Johannsson vs Z Kovacs |
| 1-0 | 38 |
1954 |
Amsterdam ol (Men) | E69 King's Indian, Fianchetto, Classical Main line |
| 7. I Johannsson vs A Fuderer |
| ½-½ | 34 |
1954 |
Amsterdam ol (Men) | A43 Old Benoni |
| 8. I Johannsson vs Z Nilsson |
 | 0-1 | 23 |
1954 |
Amsterdam ol (Men) | D47 Queen's Gambit Declined Semi-Slav |
| 9. I Johannsson vs R Bobekov |
| 0-1 | 41 |
1954 |
Amsterdam | B93 Sicilian, Najdorf, 6.f4 |
| 10. E Gereben vs I Johannsson |
| 1-0 | 39 |
1954 |
Amsterdam ol (Men) | E66 King's Indian, Fianchetto, Yugoslav Panno |
| 11. Kotov vs I Johannsson |
| 1-0 | 29 |
1954 |
Amsterdam ol (Men) | E72 King's Indian |
| 12. H Kramer vs I Johannsson |
| ½-½ | 20 |
1954 |
Amsterdam ol (Men) | C90 Ruy Lopez, Closed |
| 13. P Clarke vs I Johannsson |
| 1-0 | 40 |
1954 |
Amsterdam | B93 Sicilian, Najdorf, 6.f4 |
| 14. I Johannsson vs Portisch |
| 0-1 | 26 |
1955 |
Wch U20 prel-B | E15 Queen's Indian |
| 15. I Johannsson vs Tringov |
| ½-½ | 28 |
1955 |
Wch U20 prel-B | E69 King's Indian, Fianchetto, Classical Main line |
| 16. S Schweber vs I Johannsson |
| ½-½ | 41 |
1955 |
Wch U20 prel-B | C88 Ruy Lopez |
| 17. A Dueckstein vs I Johannsson |
| 1-0 | 28 |
1956 |
Moscow ol (Men) | B39 Sicilian, Accelerated Fianchetto, Breyer Variation |
| 18. I Johannsson vs J Penrose |
| ½-½ | 26 |
1956 |
Moscow | A07 King's Indian Attack |
| 19. Schmid vs I Johannsson |
| 0-1 | 39 |
1956 |
Moscow ol (Men) prel | B64 Sicilian, Richter-Rauzer Attack |
| 20. A Nielsen vs I Johannsson |
| 0-1 | 41 |
1956 |
Copenhagen | B88 Sicilian, Fischer-Sozin Attack |
| 21. Julio Bolbochan vs I Johannsson |
| ½-½ | 44 |
1956 |
Olympiad | A16 English |
| 22. I Johannsson vs S Dittmann |
| 1-0 | 31 |
1956 |
Moscow ol (Men) | E62 King's Indian, Fianchetto |
| 23. Larsen vs I Johannsson |
| 1-0 | 43 |
1956 |
Copenhagen | E65 King's Indian, Fianchetto, Yugoslav, 7.O-O |
| 24. I Johannsson vs G Palmason |
| 1-0 | 44 |
1957 |
Reykjavik | A88 Dutch, Leningrad, Main Variation with c6 |
| 25. I Asmundsson vs I Johannsson |
| ½-½ | 13 |
1957 |
Reykjavik | C71 Ruy Lopez |