| Game |
| Result | Moves |
Year |
Event/Locale | Opening |
| 1. Janowski vs Leonhardt |
 | 1-0 | 30 |
1905 |
Ostend | D60 Queen's Gambit Declined, Orthodox Defense |
| 2. Maroczy vs Leonhardt |
| 1-0 | 34 |
1905 |
Ostend | D63 Queen's Gambit Declined, Orthodox Defense |
| 3. Marshall vs Leonhardt |
| 0-1 | 60 |
1905 |
Ostend | D51 Queen's Gambit Declined |
| 4. Tarrasch vs Leonhardt |
| 1-0 | 26 |
1905 |
Ostend | D55 Queen's Gambit Declined |
| 5. Marshall vs Leonhardt |
| 1-0 | 49 |
1906 |
DSB Kongress XV | D61 Queen's Gambit Declined, Orthodox, Rubinstein Attack |
| 6. Vidmar vs Leonhardt |
| 0-1 | 47 |
1907 |
Carlsbad it, CZE | D55 Queen's Gambit Declined |
| 7. Rubinstein vs Leonhardt |
| 1-0 | 82 |
1908 |
Prague | D61 Queen's Gambit Declined, Orthodox, Rubinstein Attack |
| 8. Alapin vs Leonhardt |
| ½-½ | 115 |
1908 |
Prague | D60 Queen's Gambit Declined, Orthodox Defense |
| 9. Vidmar vs Leonhardt |
| 0-1 | 43 |
1908 |
Prague | D61 Queen's Gambit Declined, Orthodox, Rubinstein Attack |
| 10. Dus Chotimirsky vs Leonhardt |
| 0-1 | 54 |
1908 |
Prague | D62 Queen's Gambit Declined, Orthodox, Rubinstein Attack |
| 11. W Von Holzhausen vs Leonhardt |
| 1-0 | 31 |
1927 |
25. DSB Kongress | D55 Queen's Gambit Declined |
| 12. B Koch vs Leonhardt |
| ½-½ | 26 |
1928 |
It BSG | D55 Queen's Gambit Declined |
