| Trecate to Olympia Heights (Florida) | 4,931.17 mi (7,935.95 km) |
| Trecate to Omaha (Nebraska) | 4,865.07 mi (7,829.58 km) |
| Trecate to On Top of the World Designated Place (Florida) | 4,863.41 mi (7,826.91 km) |
| Trecate to Onalaska (Wisconsin) | 4,560.78 mi (7,339.87 km) |
| Trecate to Oneida (New York) | 3,975.98 mi (6,398.72 km) |
| Trecate to Oneonta (New York) | 3,975.12 mi (6,397.34 km) |
| Trecate to Ontario (California) | 6,003.67 mi (9,661.98 km) |
| Trecate to Ontario (Oregon) | 5,418.74 mi (8,720.62 km) |
| Trecate to Opa-locka (Florida) | 4,919.16 mi (7,916.62 km) |
| Trecate to Opelika (Alabama) | 4,836.05 mi (7,782.86 km) |
| Trecate to Opelousas (Louisiana) | 5,224.50 mi (8,408.02 km) |
| Trecate to Orange (California) | 6,024.08 mi (9,694.82 km) |
| Trecate to Orange (Texas) | 5,315.00 mi (8,553.67 km) |
| Trecate to Orange City (Florida) | 4,826.26 mi (7,767.12 km) |
| Trecate to Orangeburg (South Carolina) | 4,601.28 mi (7,405.04 km) |
