| Greenock to Orangevale (California) | 4,915.53 mi (7,910.78 km) |
| Greenock to Orchards (Washington) | 4,543.12 mi (7,311.44 km) |
| Greenock to Orcutt (California) | 5,116.45 mi (8,234.14 km) |
| Greenock to Oregon (Ohio) | 3,505.62 mi (5,641.75 km) |
| Greenock to Oregon (Wisconsin) | 3,657.61 mi (5,886.35 km) |
| Greenock to Oregon City (Oregon) | 4,564.89 mi (7,346.49 km) |
| Greenock to Orem (Utah) | 4,539.54 mi (7,305.69 km) |
| Greenock to Orinda (California) | 4,990.30 mi (8,031.11 km) |
| Greenock to Orland Park (Illinois) | 3,668.48 mi (5,903.85 km) |
| Greenock to Orlando (Florida) | 4,102.70 mi (6,602.66 km) |
| Greenock to Ormond Beach (Florida) | 4,049.82 mi (6,517.56 km) |
| Greenock to Oro Valley (Arizona) | 4,961.23 mi (7,984.32 km) |
| Greenock to Oroville (California) | 4,877.69 mi (7,849.88 km) |
| Greenock to Oshkosh (Wisconsin) | 3,574.55 mi (5,752.68 km) |
| Greenock to Oskaloosa (Iowa) | 3,854.10 mi (6,202.58 km) |
