| Round Lake Beach to Oakleaf Plantation (Florida) | 911.92 mi (1,467.59 km) |
| Round Lake Beach to Oakley (California) | 1,788.00 mi (2,877.51 km) |
| Round Lake Beach to Oakton (Virginia) | 613.93 mi (988.02 km) |
| Round Lake Beach to Oakville (Missouri) | 296.02 mi (476.40 km) |
| Round Lake Beach to Oatfield (Oregon) | 1,717.73 mi (2,764.42 km) |
| Round Lake Beach to Ocala (Florida) | 970.13 mi (1,561.27 km) |
| Round Lake Beach to Ocean Acres (New Jersey) | 740.75 mi (1,192.12 km) |
| Round Lake Beach to Ocean City (New Jersey) | 735.87 mi (1,184.26 km) |
| Round Lake Beach to Ocean Pines (Maryland) | 733.49 mi (1,180.44 km) |
| Round Lake Beach to Ocean Pointe (Hawaii) | 4,232.09 mi (6,810.89 km) |
| Round Lake Beach to Ocean Springs (Mississippi) | 828.03 mi (1,332.58 km) |
| Round Lake Beach to Oceanside (California) | 1,705.80 mi (2,745.22 km) |
| Round Lake Beach to Oceanside (New York) | 756.13 mi (1,216.88 km) |
| Round Lake Beach to Ocoee (Florida) | 1,021.32 mi (1,643.65 km) |
| Round Lake Beach to Oconomowoc (Wisconsin) | 54.03 mi (86.95 km) |
