| Markham to Odessa (Texas) | 1,050.65 mi (1,690.85 km) |
| Markham to Ogden (Utah) | 1,254.09 mi (2,018.27 km) |
| Markham to Oildale (California) | 1,736.74 mi (2,795.01 km) |
| Markham to Ojus (Florida) | 1,162.96 mi (1,871.60 km) |
| Markham to Okemos (Michigan) | 184.40 mi (296.77 km) |
| Markham to Oklahoma City (Oklahoma) | 678.49 mi (1,091.93 km) |
| Markham to Okmulgee (Oklahoma) | 609.95 mi (981.63 km) |
| Markham to Olathe (Kansas) | 420.08 mi (676.05 km) |
| Markham to Old Jamestown (Missouri) | 234.74 mi (377.77 km) |
| Markham to Oldsmar (Florida) | 978.04 mi (1,574.00 km) |
| Markham to Olean (New York) | 477.49 mi (768.45 km) |
| Markham to Olive Branch (Mississippi) | 473.34 mi (761.77 km) |
| Markham to Olivehurst (California) | 1,780.53 mi (2,865.49 km) |
| Markham to Olney (Maryland) | 583.65 mi (939.29 km) |
| Markham to Olympia (Washington) | 1,764.66 mi (2,839.95 km) |
