| Rossmoor to Olympia (Washington) | 949.60 mi (1,528.23 km) |
| Rossmoor to Olympia Heights (Florida) | 2,317.67 mi (3,729.92 km) |
| Rossmoor to Omaha (Nebraska) | 1,308.11 mi (2,105.19 km) |
| Rossmoor to On Top of the World Designated Place (Florida) | 2,123.79 mi (3,417.91 km) |
| Rossmoor to Onalaska (Wisconsin) | 1,596.03 mi (2,568.57 km) |
| Rossmoor to Oneida (New York) | 2,356.61 mi (3,792.60 km) |
| Rossmoor to Oneonta (New York) | 2,386.33 mi (3,840.43 km) |
| Rossmoor to Ontario (California) | 32.22 mi (51.85 km) |
| Rossmoor to Ontario (Oregon) | 709.79 mi (1,142.30 km) |
| Rossmoor to Opa-locka (Florida) | 2,317.75 mi (3,730.06 km) |
| Rossmoor to Opelika (Alabama) | 1,883.87 mi (3,031.80 km) |
| Rossmoor to Opelousas (Louisiana) | 1,533.24 mi (2,467.51 km) |
| Rossmoor to Orange (California) | 14.88 mi (23.95 km) |
| Rossmoor to Orange (Texas) | 1,444.50 mi (2,324.70 km) |
| Rossmoor to Orange City (Florida) | 2,184.80 mi (3,516.09 km) |
