| Lac to Olympia Heights (Florida) | 5,538.72 mi (8,913.71 km) |
| Lac to Omaha (Nebraska) | 5,445.68 mi (8,763.97 km) |
| Lac to On Top of the World Designated Place (Florida) | 5,472.08 mi (8,806.46 km) |
| Lac to Onalaska (Wisconsin) | 5,143.27 mi (8,277.29 km) |
| Lac to Oneida (New York) | 4,577.97 mi (7,367.54 km) |
| Lac to Oneonta (New York) | 4,578.40 mi (7,368.23 km) |
| Lac to Ontario (California) | 6,548.93 mi (10,539.48 km) |
| Lac to Ontario (Oregon) | 5,938.24 mi (9,556.68 km) |
| Lac to Opa-locka (Florida) | 5,526.76 mi (8,894.47 km) |
| Lac to Opelika (Alabama) | 5,442.50 mi (8,758.85 km) |
| Lac to Opelousas (Louisiana) | 5,828.14 mi (9,379.49 km) |
| Lac to Orange (California) | 6,569.22 mi (10,572.13 km) |
| Lac to Orange (Texas) | 5,917.56 mi (9,523.39 km) |
| Lac to Orange City (Florida) | 5,434.92 mi (8,746.67 km) |
| Lac to Orangeburg (South Carolina) | 5,209.15 mi (8,383.32 km) |
