| Cluj-Napoca to Olympia Heights (Florida) | 5,551.15 mi (8,933.71 km) |
| Cluj-Napoca to Omaha (Nebraska) | 5,316.35 mi (8,555.84 km) |
| Cluj-Napoca to On Top of the World Designated Place (Florida) | 5,458.65 mi (8,784.85 km) |
| Cluj-Napoca to Onalaska (Wisconsin) | 5,020.11 mi (8,079.08 km) |
| Cluj-Napoca to Oneida (New York) | 4,514.64 mi (7,265.61 km) |
| Cluj-Napoca to Oneonta (New York) | 4,520.85 mi (7,275.61 km) |
| Cluj-Napoca to Ontario (California) | 6,354.86 mi (10,227.17 km) |
| Cluj-Napoca to Ontario (Oregon) | 5,718.32 mi (9,202.74 km) |
| Cluj-Napoca to Opa-locka (Florida) | 5,538.67 mi (8,913.63 km) |
| Cluj-Napoca to Opelika (Alabama) | 5,397.72 mi (8,686.80 km) |
| Cluj-Napoca to Opelousas (Louisiana) | 5,764.11 mi (9,276.43 km) |
| Cluj-Napoca to Orange (California) | 6,374.86 mi (10,259.34 km) |
| Cluj-Napoca to Orange (Texas) | 5,847.73 mi (9,411.01 km) |
| Cluj-Napoca to Orange City (Florida) | 5,426.77 mi (8,733.54 km) |
| Cluj-Napoca to Orangeburg (South Carolina) | 5,179.20 mi (8,335.12 km) |
