| Chicago to Odessa (Texas) | 1,060.30 mi (1,706.39 km) |
| Chicago to Ogden (Utah) | 1,252.40 mi (2,015.55 km) |
| Chicago to Oildale (California) | 1,738.11 mi (2,797.21 km) |
| Chicago to Ojus (Florida) | 1,177.89 mi (1,895.63 km) |
| Chicago to Okemos (Michigan) | 177.75 mi (286.07 km) |
| Chicago to Oklahoma City (Oklahoma) | 688.30 mi (1,107.70 km) |
| Chicago to Okmulgee (Oklahoma) | 620.77 mi (999.04 km) |
| Chicago to Olathe (Kansas) | 427.24 mi (687.57 km) |
| Chicago to Old Jamestown (Missouri) | 248.23 mi (399.49 km) |
| Chicago to Oldsmar (Florida) | 993.56 mi (1,598.98 km) |
| Chicago to Olean (New York) | 475.55 mi (765.33 km) |
| Chicago to Olive Branch (Mississippi) | 489.26 mi (787.39 km) |
| Chicago to Olivehurst (California) | 1,779.16 mi (2,863.28 km) |
| Chicago to Olney (Maryland) | 587.47 mi (945.44 km) |
| Chicago to Olympia (Washington) | 1,758.14 mi (2,829.46 km) |
