| Canals to Odessa (Texas) | 5,431.28 mi (8,740.80 km) |
| Canals to Ogden (Utah) | 5,416.48 mi (8,716.98 km) |
| Canals to Oildale (California) | 5,969.96 mi (9,607.72 km) |
| Canals to Ojus (Florida) | 4,581.90 mi (7,373.85 km) |
| Canals to Okemos (Michigan) | 4,200.71 mi (6,760.39 km) |
| Canals to Oklahoma City (Oklahoma) | 5,060.01 mi (8,143.29 km) |
| Canals to Okmulgee (Oklahoma) | 4,985.50 mi (8,023.39 km) |
| Canals to Olathe (Kansas) | 4,802.79 mi (7,729.34 km) |
| Canals to Old Jamestown (Missouri) | 4,600.03 mi (7,403.03 km) |
| Canals to Oldsmar (Florida) | 4,631.58 mi (7,453.81 km) |
| Canals to Olean (New York) | 3,946.50 mi (6,351.28 km) |
| Canals to Olive Branch (Mississippi) | 4,724.30 mi (7,603.03 km) |
| Canals to Olivehurst (California) | 5,878.46 mi (9,460.46 km) |
| Canals to Olney (Maryland) | 3,970.17 mi (6,389.37 km) |
| Canals to Olympia (Washington) | 5,514.19 mi (8,874.23 km) |
