| Olbia to Corinth (Mississippi) | 5,058.50 mi (8,140.87 km) |
| Olbia to Corinth (Texas) | 5,511.30 mi (8,869.59 km) |
| Olbia to Cornelius (North Carolina) | 4,692.46 mi (7,551.78 km) |
| Olbia to Cornelius (Oregon) | 5,785.05 mi (9,310.14 km) |
| Olbia to Corning (New York) | 4,267.24 mi (6,867.46 km) |
| Olbia to Corona (California) | 6,270.91 mi (10,092.05 km) |
| Olbia to Coronado (California) | 6,322.63 mi (10,175.29 km) |
| Olbia to Corpus Christi (Texas) | 5,779.98 mi (9,301.98 km) |
| Olbia to Corsicana (Texas) | 5,535.07 mi (8,907.84 km) |
| Olbia to Cortland (New York) | 4,212.72 mi (6,779.71 km) |
| Olbia to Corvallis (Oregon) | 5,845.62 mi (9,407.62 km) |
| Olbia to Coshocton (Ohio) | 4,547.21 mi (7,318.02 km) |
| Olbia to Costa Mesa (California) | 6,293.71 mi (10,128.75 km) |
| Olbia to Coto de Caza (California) | 6,286.29 mi (10,116.80 km) |
| Olbia to Cottage Grove (Minnesota) | 4,818.57 mi (7,754.74 km) |
