| Street to Olympia Heights (Florida) | 4,329.20 mi (6,967.18 km) |
| Street to Omaha (Nebraska) | 4,208.62 mi (6,773.12 km) |
| Street to On Top of the World Designated Place (Florida) | 4,244.72 mi (6,831.22 km) |
| Street to Onalaska (Wisconsin) | 3,904.51 mi (6,283.70 km) |
| Street to Oneida (New York) | 3,331.43 mi (5,361.41 km) |
| Street to Oneonta (New York) | 3,332.75 mi (5,363.55 km) |
| Street to Ontario (California) | 5,352.23 mi (8,613.59 km) |
| Street to Ontario (Oregon) | 4,778.42 mi (7,690.12 km) |
| Street to Opa-locka (Florida) | 4,316.83 mi (6,947.26 km) |
| Street to Opelika (Alabama) | 4,200.99 mi (6,760.84 km) |
| Street to Opelousas (Louisiana) | 4,582.35 mi (7,374.58 km) |
| Street to Orange (California) | 5,372.65 mi (8,646.45 km) |
| Street to Orange (Texas) | 4,670.99 mi (7,517.24 km) |
| Street to Orange City (Florida) | 4,210.70 mi (6,776.46 km) |
| Street to Orangeburg (South Carolina) | 3,972.98 mi (6,393.89 km) |
