| Answer | Population | % Correct |
|---|---|---|
| Oslo | 666 757 | 100%
|
| Odessa | 1 010 783 | 96%
|
| Odense | 176 683 | 77%
|
| Orléans | 114 977 | 76%
|
| Oulu | 201 124 | 73%
|
| Oxford | 151 906 | 73%
|
| Ostrava | 291 634 | 72%
|
| Oviedo | 220 567 | 68%
|
| Oldenburg | 163 830 | 58%
|
| Osnabrück | 162 403 | 54%
|
| Örebro | 117 543 | 52%
|
| Osijek | 108 048 | 45%
|
| Oostend | 71 332 | 43%
|
| Oberhausen | 210 934 | 42%
|
| Olomouc | 100 378 | 42%
|
| Offenbach am Main | 123 734 | 40%
|
| Opole | 127 792 | 38%
|
| Oradea | 196 367 | 37%
|
| Ourense | 105 893 | 34%
|
| Olsztyn | 173 599 | 33%
|
| Oryol | 319 651 | 32%
|
| Oss | 91 451 | 23%
|
| Opava | 56 450 | 20%
|
| Ostrów Wielkopolski | 71 931 | 19%
|
| Orsha | 115 938 | 17%
|
| Ostrowiec Świętokrzyski | 71 959 | 13%
|
| Obninsk | 113 639 | 9%
|
| Odintsovo | 141 493 | 8%
|
| Oleksandriia | 78 366 | 8%
|
| Orekhovo-Zuyevo | 119 956 | 6%
|