| Olbia to Carson (California) | 6,296.05 mi (10,132.51 km) |
| Olbia to Carson City (Nevada) | 6,049.02 mi (9,734.96 km) |
| Olbia to Carteret (New Jersey) | 4,196.64 mi (6,753.84 km) |
| Olbia to Cartersville (Georgia) | 4,925.09 mi (7,926.16 km) |
| Olbia to Carthage (Missouri) | 5,211.40 mi (8,386.94 km) |
| Olbia to Cary (Illinois) | 4,741.01 mi (7,629.92 km) |
| Olbia to Cary (North Carolina) | 4,585.27 mi (7,379.27 km) |
| Olbia to Casa de Oro-Mount Helix (California) | 6,310.43 mi (10,155.65 km) |
| Olbia to Casa Grande (Arizona) | 6,113.13 mi (9,838.14 km) |
| Olbia to Casas Adobes (Arizona) | 6,114.47 mi (9,840.28 km) |
| Olbia to Cascades (Virginia) | 4,395.11 mi (7,073.25 km) |
| Olbia to Casper (Wyoming) | 5,404.99 mi (8,698.49 km) |
| Olbia to Casselberry (Florida) | 4,992.92 mi (8,035.32 km) |
| Olbia to Castaic (California) | 6,273.10 mi (10,095.58 km) |
| Olbia to Castle Pines (Colorado) | 5,519.85 mi (8,883.34 km) |
