| Potomac to Oakleaf Plantation (Florida) | 665.42 mi (1,070.89 km) |
| Potomac to Oakley (California) | 2,382.87 mi (3,834.86 km) |
| Potomac to Oakton (Virginia) | 10.41 mi (16.75 km) |
| Potomac to Oakville (Missouri) | 707.92 mi (1,139.29 km) |
| Potomac to Oatfield (Oregon) | 2,333.01 mi (3,754.62 km) |
| Potomac to Ocala (Florida) | 736.08 mi (1,184.61 km) |
| Potomac to Ocean Acres (New Jersey) | 163.55 mi (263.22 km) |
| Potomac to Ocean City (New Jersey) | 140.02 mi (225.33 km) |
| Potomac to Ocean Pines (Maryland) | 118.55 mi (190.79 km) |
| Potomac to Ocean Pointe (Hawaii) | 4,827.69 mi (7,769.42 km) |
| Potomac to Ocean Springs (Mississippi) | 885.75 mi (1,425.48 km) |
| Potomac to Oceanside (California) | 2,255.75 mi (3,630.28 km) |
| Potomac to Oceanside (New York) | 219.41 mi (353.11 km) |
| Potomac to Ocoee (Florida) | 762.51 mi (1,227.15 km) |
| Potomac to Oconomowoc (Wisconsin) | 652.19 mi (1,049.60 km) |
