| Delaware to Odessa (Texas) | 1,218.99 mi (1,961.78 km) |
| Delaware to Ogden (Utah) | 1,506.68 mi (2,424.77 km) |
| Delaware to Oildale (California) | 1,976.12 mi (3,180.26 km) |
| Delaware to Ojus (Florida) | 1,004.11 mi (1,615.95 km) |
| Delaware to Okemos (Michigan) | 181.04 mi (291.35 km) |
| Delaware to Oklahoma City (Oklahoma) | 853.63 mi (1,373.78 km) |
| Delaware to Okmulgee (Oklahoma) | 774.02 mi (1,245.67 km) |
| Delaware to Olathe (Kansas) | 632.43 mi (1,017.80 km) |
| Delaware to Old Jamestown (Missouri) | 396.73 mi (638.47 km) |
| Delaware to Oldsmar (Florida) | 845.64 mi (1,360.92 km) |
| Delaware to Olean (New York) | 271.38 mi (436.75 km) |
| Delaware to Olive Branch (Mississippi) | 521.88 mi (839.89 km) |
| Delaware to Olivehurst (California) | 2,031.79 mi (3,269.85 km) |
| Delaware to Olney (Maryland) | 328.51 mi (528.69 km) |
| Delaware to Olympia (Washington) | 2,021.18 mi (3,252.78 km) |
