| Rancho Santa Margarita to Oskaloosa (Iowa) | 1,461.15 mi (2,351.50 km) |
| Rancho Santa Margarita to Oswego (Illinois) | 1,684.80 mi (2,711.42 km) |
| Rancho Santa Margarita to Oswego (New York) | 2,296.50 mi (3,695.86 km) |
| Rancho Santa Margarita to Otsego (Minnesota) | 1,502.02 mi (2,417.27 km) |
| Rancho Santa Margarita to Ottawa (Illinois) | 1,656.10 mi (2,665.23 km) |
| Rancho Santa Margarita to Ottawa (Kansas) | 1,289.39 mi (2,075.07 km) |
| Rancho Santa Margarita to Ottumwa (Iowa) | 1,468.28 mi (2,362.96 km) |
| Rancho Santa Margarita to Overland (Missouri) | 1,552.52 mi (2,498.55 km) |
| Rancho Santa Margarita to Overland Park (Kansas) | 1,323.11 mi (2,129.34 km) |
| Rancho Santa Margarita to Overlea (Maryland) | 2,295.80 mi (3,694.73 km) |
| Rancho Santa Margarita to Oviedo (Florida) | 2,169.17 mi (3,490.93 km) |
| Rancho Santa Margarita to Owasso (Oklahoma) | 1,243.50 mi (2,001.22 km) |
| Rancho Santa Margarita to Owatonna (Minnesota) | 1,488.81 mi (2,396.01 km) |
| Rancho Santa Margarita to Owensboro (Kentucky) | 1,726.19 mi (2,778.03 km) |
| Rancho Santa Margarita to Owings Mills (Maryland) | 2,281.02 mi (3,670.95 km) |
