| Owings Mills to Orangeburg (South Carolina) | 467.35 mi (752.12 km) |
| Owings Mills to Orangevale (California) | 2,359.96 mi (3,797.99 km) |
| Owings Mills to Orchards (Washington) | 2,335.44 mi (3,758.53 km) |
| Owings Mills to Orcutt (California) | 2,400.08 mi (3,862.56 km) |
| Owings Mills to Oregon (Ohio) | 381.42 mi (613.84 km) |
| Owings Mills to Oregon (Wisconsin) | 697.92 mi (1,123.19 km) |
| Owings Mills to Oregon City (Oregon) | 2,341.02 mi (3,767.51 km) |
| Owings Mills to Orem (Utah) | 1,840.52 mi (2,962.03 km) |
| Owings Mills to Orinda (California) | 2,425.47 mi (3,903.42 km) |
| Owings Mills to Orland Park (Illinois) | 600.54 mi (966.48 km) |
| Owings Mills to Orlando (Florida) | 798.84 mi (1,285.60 km) |
| Owings Mills to Ormond Beach (Florida) | 740.47 mi (1,191.67 km) |
| Owings Mills to Oro Valley (Arizona) | 1,960.29 mi (3,154.78 km) |
| Owings Mills to Oroville (California) | 2,363.13 mi (3,803.10 km) |
| Owings Mills to Oshkosh (Wisconsin) | 684.67 mi (1,101.87 km) |
