| Glen Burnie to Olympia Heights (Florida) | 952.98 mi (1,533.67 km) |
| Glen Burnie to Omaha (Nebraska) | 1,034.12 mi (1,664.26 km) |
| Glen Burnie to On Top of the World Designated Place (Florida) | 766.18 mi (1,233.05 km) |
| Glen Burnie to Onalaska (Wisconsin) | 821.53 mi (1,322.12 km) |
| Glen Burnie to Oneida (New York) | 275.33 mi (443.10 km) |
| Glen Burnie to Oneonta (New York) | 241.75 mi (389.06 km) |
| Glen Burnie to Ontario (California) | 2,282.00 mi (3,672.53 km) |
| Glen Burnie to Ontario (Oregon) | 2,091.68 mi (3,366.23 km) |
| Glen Burnie to Opa-locka (Florida) | 940.01 mi (1,512.80 km) |
| Glen Burnie to Opelika (Alabama) | 664.39 mi (1,069.23 km) |
| Glen Burnie to Opelousas (Louisiana) | 1,058.56 mi (1,703.59 km) |
| Glen Burnie to Orange (California) | 2,299.40 mi (3,700.53 km) |
| Glen Burnie to Orange (Texas) | 1,154.69 mi (1,858.29 km) |
| Glen Burnie to Orange City (Florida) | 755.05 mi (1,215.13 km) |
| Glen Burnie to Orangeburg (South Carolina) | 457.40 mi (736.11 km) |
