| Gary to Orangevale (California) | 1,788.86 mi (2,878.89 km) |
| Gary to Orchards (Washington) | 1,767.28 mi (2,844.16 km) |
| Gary to Orcutt (California) | 1,841.95 mi (2,964.34 km) |
| Gary to Oregon (Ohio) | 202.25 mi (325.49 km) |
| Gary to Oregon (Wisconsin) | 139.31 mi (224.19 km) |
| Gary to Oregon City (Oregon) | 1,771.88 mi (2,851.57 km) |
| Gary to Orem (Utah) | 1,269.83 mi (2,043.60 km) |
| Gary to Orinda (California) | 1,855.61 mi (2,986.32 km) |
| Gary to Orland Park (Illinois) | 26.61 mi (42.83 km) |
| Gary to Orlando (Florida) | 967.07 mi (1,556.35 km) |
| Gary to Ormond Beach (Florida) | 918.51 mi (1,478.20 km) |
| Gary to Oro Valley (Arizona) | 1,443.12 mi (2,322.48 km) |
| Gary to Oroville (California) | 1,790.49 mi (2,881.51 km) |
| Gary to Oshkosh (Wisconsin) | 178.97 mi (288.02 km) |
| Gary to Oskaloosa (Iowa) | 274.88 mi (442.38 km) |
