| Markham to Orangevale (California) | 1,771.14 mi (2,850.37 km) |
| Markham to Orchards (Washington) | 1,750.51 mi (2,817.18 km) |
| Markham to Orcutt (California) | 1,824.31 mi (2,935.94 km) |
| Markham to Oregon (Ohio) | 219.94 mi (353.95 km) |
| Markham to Oregon (Wisconsin) | 126.21 mi (203.12 km) |
| Markham to Oregon City (Oregon) | 1,755.04 mi (2,824.46 km) |
| Markham to Orem (Utah) | 1,252.10 mi (2,015.06 km) |
| Markham to Orinda (California) | 1,837.88 mi (2,957.78 km) |
| Markham to Orland Park (Illinois) | 8.88 mi (14.28 km) |
| Markham to Orlando (Florida) | 974.59 mi (1,568.45 km) |
| Markham to Ormond Beach (Florida) | 926.59 mi (1,491.20 km) |
| Markham to Oro Valley (Arizona) | 1,426.53 mi (2,295.78 km) |
| Markham to Oroville (California) | 1,772.81 mi (2,853.06 km) |
| Markham to Oshkosh (Wisconsin) | 173.12 mi (278.61 km) |
| Markham to Oskaloosa (Iowa) | 257.21 mi (413.94 km) |
