| Howard to Olympia Heights (Florida) | 1,372.25 mi (2,208.43 km) |
| Howard to Omaha (Nebraska) | 462.79 mi (744.80 km) |
| Howard to On Top of the World Designated Place (Florida) | 1,114.92 mi (1,794.29 km) |
| Howard to Onalaska (Wisconsin) | 161.23 mi (259.48 km) |
| Howard to Oneida (New York) | 627.55 mi (1,009.94 km) |
| Howard to Oneonta (New York) | 668.09 mi (1,075.19 km) |
| Howard to Ontario (California) | 1,725.02 mi (2,776.15 km) |
| Howard to Ontario (Oregon) | 1,421.32 mi (2,287.40 km) |
| Howard to Opa-locka (Florida) | 1,362.11 mi (2,192.10 km) |
| Howard to Opelika (Alabama) | 835.66 mi (1,344.87 km) |
| Howard to Opelousas (Louisiana) | 994.38 mi (1,600.30 km) |
| Howard to Orange (California) | 1,744.34 mi (2,807.25 km) |
| Howard to Orange (Texas) | 1,044.97 mi (1,681.72 km) |
| Howard to Orange City (Florida) | 1,143.04 mi (1,839.55 km) |
| Howard to Orangeburg (South Carolina) | 857.17 mi (1,379.48 km) |
