| Ottawa to Oakleaf Plantation (Florida) | 865.90 mi (1,393.53 km) |
| Ottawa to Oakley (California) | 1,752.73 mi (2,820.75 km) |
| Ottawa to Oakton (Virginia) | 631.73 mi (1,016.68 km) |
| Ottawa to Oakville (Missouri) | 215.93 mi (347.50 km) |
| Ottawa to Oatfield (Oregon) | 1,705.75 mi (2,745.15 km) |
| Ottawa to Ocala (Florida) | 921.05 mi (1,482.28 km) |
| Ottawa to Ocean Acres (New Jersey) | 770.79 mi (1,240.47 km) |
| Ottawa to Ocean City (New Jersey) | 762.24 mi (1,226.71 km) |
| Ottawa to Ocean Pines (Maryland) | 752.85 mi (1,211.60 km) |
| Ottawa to Ocean Pointe (Hawaii) | 4,198.18 mi (6,756.31 km) |
| Ottawa to Ocean Springs (Mississippi) | 756.39 mi (1,217.29 km) |
| Ottawa to Oceanside (California) | 1,654.32 mi (2,662.37 km) |
| Ottawa to Oceanside (New York) | 792.70 mi (1,275.72 km) |
| Ottawa to Ocoee (Florida) | 973.60 mi (1,566.86 km) |
| Ottawa to Oconomowoc (Wisconsin) | 121.69 mi (195.84 km) |
