| Population | Country | City | % Correct |
|---|---|---|---|
| 899,000 | Norway | Oslo | 99%
|
| 17,175,000 | Japan | Osaka | 96%
|
| 948,000 | Canada | Ottawa | 90%
|
| 1,931,000 | United States | Orlando | 83%
|
| 1,010,000 | Ukraine | Odessa | 78%
|
| 901,000 | United States | Oklahoma City | 71%
|
| 2,193,000 | Burkina Faso | Ouagadougou | 67%
|
| 732,000 | United States | Omaha | 52%
|
| 1,148,000 | Russia | Omsk | 49%
|
| 480,000 | Czech Republic | Ostrava | 27%
|
| 650,000 | Japan | Okayama | 14%
|
| 540,000 | Russia | Orenburg | 13%
|
| 908,000 | Nigeria | Onitsha | 12%
|
| 556,000 | United States | Ogden | 11%
|
| 180,000 | United States | Olympia | 10%
|
| 369,000 | United States | Oxnard | 7%
|
| 161,000 | United States | Ocala | 6%
|
| 410,000 | Japan | Oita | 5%
|
| 500,000 | Nigeria | Oyo | 4%
|
| 775,000 | Japan | Otsu | 1%
|