| Round Rock to Castle Pines (Colorado) | 739.35 mi (1,189.86 km) |
| Round Rock to Castle Rock (Colorado) | 733.98 mi (1,181.22 km) |
| Round Rock to Castro Valley (California) | 1,475.99 mi (2,375.38 km) |
| Round Rock to Catalina Foothills (Arizona) | 788.58 mi (1,269.09 km) |
| Round Rock to Cataño (Puerto Rico) | 2,141.24 mi (3,445.99 km) |
| Round Rock to Cathedral City (California) | 1,121.20 mi (1,804.40 km) |
| Round Rock to Catonsville (Maryland) | 1,326.02 mi (2,134.02 km) |
| Round Rock to Cave Spring (Virginia) | 1,111.23 mi (1,788.35 km) |
| Round Rock to Cayce (South Carolina) | 998.45 mi (1,606.85 km) |
| Round Rock to Cayey (Puerto Rico) | 2,151.03 mi (3,461.76 km) |
| Round Rock to Cedar City (Utah) | 1,009.94 mi (1,625.34 km) |
| Round Rock to Cedar Falls (Iowa) | 877.18 mi (1,411.69 km) |
| Round Rock to Cedar Hill (Texas) | 147.86 mi (237.96 km) |
| Round Rock to Cedar Lake (Indiana) | 941.02 mi (1,514.43 km) |
| Round Rock to Cedar Mill (Oregon) | 1,704.34 mi (2,742.87 km) |
